The Celestron Advanced VX mount is great small equatorial goto mount. But unlike many other mounts, it does not have a built-in bubble level. In fact, there isn't really any good flat level surface on the AVX mount to place a bubble level!
The solution is this AVX Bubble Level from durable PLA plastic to custom fit an angled block on the front of the AVX mount. It can be attached with included double-sided foam adhesive tape. The "arms" on the side of the AVX level ensure the level goes on perfectly square. The bubble level is easy to read and recessed in the AVX Level plastic body to protect it. The AVX Level is easy to see even when the mount is fully assembled.
