NATIONAL GEOGRAPHIC Hobby Rock Tumbler Kit – Durable Leak-Proof Rock Polisher with 7-Day Timer – Complete Rock Tumbling Kit – Geology Hobby for Kids, Educational STEM Science Kit, Rock Collection

Are you wondering if it works well? It does!Any problems? None!Results? Incredible, I was truly shocked!Pros:Almost no assembly, at all.Extremely easy to understand the directions(Tumbling time will vary depending on the rocks. Don't let it scare you away when it says one phase should tumble for 6-8 days (I haven't had to tumble any that long! The longest has been 3 days). That being said, an extremely hard rock that's very jagged may need more time. Using the rocks they include, or your own collection of crystals/gemstones is a great route. A plain piece of gravel or a rock of that type is very hard and dense and may take more time (who wants polished gravel anyway though?)Extended project to do with children, lots of engagement. Because their are 4 different grit types with different purposes, the children get to return to their project, dump the rocks and check on the progress and start a new phase. It's a great opportunity to teach to teach about erosion, and show / explain what a rock looks like through millions of years of erosion and then further explain how incredible it is that we are doing this project together that mimics what nature does, we are polishing these rocks in a few weeks that takes millions of years to do in nature! It's a wonderful learning opportunity for children, as well as an extremely engaging project that although it may take quite some time for it to finish, the ongoing project itself is what makes it fun. Returning to the rocks and seeing the progress, (we actually started taking pictures each time we open it so then we can look back on the pictures and see how the rocks have changed!). I cannot say enough how great of a project this is for children to get them excited about science!Personally, I find this to be very satisfying regardless of children. This would be an extremely fun hobby for an adult as well, the above is not to say that this is a children only experience. Use or find or buy your own natural gemstones or softer rocks (look in River beds if you can!). Tumble them, polish them, and then make your jewelry or just save them to display. It's quite a satisfying feeling to see the project from beginning to end, and to know that the beautiful smooth shiny rocks were not store-bought, but that you did this with that with this machine!Cons:I've been through the tumbling process in full, twice now. I honestly cannot think of any cons at this point. It's not to say that no one has had issues, but the machine I received functions perfectly and I have had no issues with leaks or ill-fitting pieces, tearing of the belt or anything of this nature.I did take a very small amount of oil on my fingertip and lightly rub it on the belt to keep it lubricated, with the constant friction I could see how the belt can eventually wear down just like any other belt of this nature whether it's in a car or in a fan. So, keeping it very slightly lubricated will help with the health of the band. Should it break, the kid includes an extra belt and it is incredibly easy to repair, the belt is divisible and an outside piece of the equipment you simply take one off and put the other on there is no sophisticated way of connecting the belt, it is truly something my six-year-old could do with almost no instruction, so an adult will have zero issues with that!If you are interested in rock tumbling, or you just want a very fun project for your children to stimulate their interest in science or to just keep them busy using their imaginations (regarding the possibilities of what to do with the rocks, and imagining whether it will look like and the brilliant colors!) - then this is absolutely a perfect kit to start with.DO:Make sure to not put too many rocks. I've never filled mine more than one third of the way, and I wouldn't recommend doing more than that. The amount of rocks you can tumble at a time will vary depending on the size, but I also recommend not doing anything smaller than a dime because during the tumbling process it could crack and chip. I would also recommend not doing anything larger than a half dollar as well (height and width, and that'd be on the largest size). Remember, this is just the hobby edition. I do have to say though, the results are quite sophisticated for just a hobby edition!All in all, it's an excellent piece of equipment to buy if you're interested in rock tumbling but are unsure if you would stick to it or are not ready to spend a few hundred dollars on a professional Tumbler.** I did read a few comments about the machine leaking, I have not had this problem at any point. Make sure you are putting on the inner lid correctly, as well as the top lid, then turning the black lid securing piece as tightly as possible. If you do end up having problems, I highly recommend exchanging instead of giving up, because I really have seen that it works and I just want everyone who wants to try this to have the experience I've had!It's been great fun. Wonderful purchase, no regrets!

**updated review below--- we got shiny rocks!**We bought this for our son as a 7th birthday gift. It's the perfect mid-range rock tumbler! It's sturdy and doesn't seem like it will break. It's been running now for over 2 weeks. It's definitely not silent, but with its rubber barrel, I suspect it's tougher and quieter than one with a plastic barrel. We keep it in the basement, but can see it'd be annoying if it was somewhere in the house. It has a handy feature where you can set it for up to 7 days and it'll tell you how many days are left- great for a kid! It includes a nice little instruction manual with information about the history of rock tumbling and description of the rocks included. It's a nice, reasonably-priced kit that includes everything you need to start tumbling rocks right away!Update: now that we've completed a batch, I figured I'd add some info. We still think it's a nice kit! The little sieve that comes with the kit is very handy! Our final stones were smooth and lovely. However, they weren't really shiny. After some reading, we learned that there is a bit of an art to this and we need to be a little more meticulous in the cleaning of the tumbler between grits. Overall, though, our 7-year-old is quite pleased with the kit. We bought the jasper set and will try that next!Update #2-- SHINY ROCKS!We did a few batches and couldn't get shiny rocks and we lost interest. My kiddo is now almost 9 but just started becoming interested in geology a lot more. We decided to try again. After reading some about it, I decided to try a better brand of grit and IT WORKED! We bought Rock Tumbler Grit for 3 Pound Tumblerby Professional Grade Rock Polishing GritAnd followed the instructions **carefully,** making sure to clean the tumbler tub very meticulously after each tumble. We also purchased tumbling pellets (Rock Tumbler "Sinking" Plastic Pellets / Beads Used For Final Polishing & Burnishing Stages) for the final two stages. The new grit had an additional stage which made all the difference. The jade set came out mostly lovely and shiny. They were not all consistently shiny, but I see promise! I added a picture using the flash to show off the polish. We're going to try the nee grit with a different set of stones now.

Great little tumbler! Very easy to set up and use. The rocks in the pic were from round 1, after 5 days. They look shiny because they were wet. When they dry, they had a haze on them. They don't get polished to a shine until step 4.This set comes with everything you need to get started, including the grit and stones. The stones in the photo are a mix of ones I already had, and the ones that come with the set.The set comes with enough polish to do one full round and all 4 steps of tumbling. I have read reviews that say the Step 4 polish doesn't work well, so I went ahead and purchased a new set of grinding and polishing grit from another company. I have not tested that out yet.Just a warning that you need patience, as each step takes about a week.Plus, you'll need an outdoor location where it will be safe from rain. It is too loud to keep in the house! We have it in the garage and it's not bad in there, but very noticeable. You can even hear it a little bit in the house, when the house is quiet, as it is against the wall of the garage.This is my first experience with a rock tumbler, and I've wanted one since I was a kid! It's really neat so far, and I look forward to finding new stones to tumble.Technically I did get this for my son as a gift. He was very excited when he got it, and then again when the stones came out after the first round. Everything in between is not very exciting, lol.