Hubbell-Raco 5406-0 Weatherproof Extension Box, 1 Gang, 18.3 Cu-in X 4-1/2 in L X 2-3/4 in W X 1 in D Grey

Extension was not available locally. This spacer allowed me to install a safety switch on my tablesaw

properly made extra room for my wires. comes with seals, perfect for what i needed

This appears to be the exact same extension box carried in the big box stores, except I didn't have to hunt around for it or worry whether there would be any in stock. (For whatever reason, my neighborhood hardware store had a bunch for the same price as big box store and here). I wish it were a little bigger when installing weather resistant GFCIs, but it is what it is.

I needed additional space in an outside electrical box and I was not able to find these water proof extensions at any of the big package stores or our local hardware. We ordered these an in a few days we were able to assemble our system and we have been running for almost a year with them.

It worked for me just fine, but the gasket that came with extension was not helpful. It was designed for a flat surface. My application involved a stone wall... a generally rough, uneven surface. No big deal though. I threw away the gasket and used more silicone sealer. Looks good.

This worked perfectly on my 30-Amp RV outlet that I flush-mounted on the exterior wall. I wanted a bit more room between the back of the receptacle and the back of the weather-proof, single-gang box.

This box extension is just what I needed to install a bulky smart outlet in an outdoor box. I have two in place.

Exactly what I needed to fit gfci outlet outside. Could not find at lowes. Weird.