Eyepiece 44-49mm & Objective lens 55-59mm

The build quality of the rubber is very excellent and elastic. The finish is very good and fits very tightly. The flip-up cover spring is very good and the cover for the front flips all the way back up to 45 degrees , wile the cover on the back when it flips up to 90 degrees and I had to make a minor adjustment with the dremmel tool so it can go back further to 45 degrees making room for my hat. Overall works very good and will not come off unless you use a bit of force. Worth the money.

Perfect for my Arken EPL-4 scope. Easy to take on and off and seem to be durable. This company is quickly becoming a go to for my optics. Great value, lightweight and not bulky.

Fit perfect and stay closed.

Good product...objective is solid and tight. Ocular cap is loose and slides when opening...they close securely so may loosen up some. I have removed and cleaned it and ocular surface with alcohol to remove any film or dust...to see if would get more secure. Still working...might rough it up some on inside of rubber sleeve or try to clean with acetone to see if better surface contact. Otherwise are outstanding in function and ability to seal.

Very good quality and protects my rifle scope easy to install

These caps are 1000% more robust then a butler creek scoop cap. the build quality is amazing. I was only going to give this a 4 star but i changed my mind while writing this. my issue is really more of a pet peeve than anything. this cap has a rubber boot that holds it to the diopter (which is a really good idea as it really holds on). when trying to rotate the diopter the rubber torques but not the diopter since the rubber is holding the more of the tube then the diopter ring. so when rotating it the cap come off the end of the diopter a bit. it does snap back when you let go. you just have to make more of an effort to rotate the diopter then on say a butler creek

Fit the sh4j perfectly

Once the optic was installed on my rifle, these easily slid on and stay on. They are easy to open and close and haven't popped open on their own when I didn't want them to. It isn't really a negative, but two notes from my experience: 1.) If you will be shooting with others or sometimes wear glasses and sometimes don't, adjusting the optic focus ring is annoying with these on. You have to remove the flip it, make your adjustment, then reinstall. Once you dial your optic in if you're not sharing a rifle or have variable vision situations like glasses / no glasses this won't impact you. 2.) There is a mechanical first stop on the flip it that faces you so it stops at 180 degrees (straight up) instead of 270 degrees (laying on top of the optic). I don't understand why you would want the 180 stop, and the front cover does not have this. The first time I used them I didn't realize you could push past the 180 degrees and didn't want to force it, so it kept hitting the bill of my hat when I would shoot. This is not an issue now that I've discovered you can simply snap it to the next setting and it will be out of the way but is a weird design IMO. Overall they are easy to install and use, do their job, and look cool. Five stars in my book.

Ordered 2 sets of the large sizes for 2 different scope brands, one DNT the one, and one Vortex venom 5x25. Install was easy on both, and fitment was spot on for both scopes.

I got 2 sets. they are great. love they lay flat and flip up easily. need killflash inserts