Very nice but - Vector Optics Universal Flat Bubble ACD Mount

These little bubble levels are very nice and the little strap it comes with is useful in some way I guess. The only problem I have with these, are the ribs that run along the housing. They are not spaced wide enough for the pic rail tooth to sit between them and they are not wide or big enough, or in the correct clock position to sit in the slot of a pic rail. So they are hard as heck to get stable unless you use the holes in the levels to put a string through and kind of tie it around the firearm and the rail / scope. But I really like these little levels, what can you expect for such a low price, they can't make it fit perfect for every use, not for the price. They could update them with a housing that will sit on pic rail tooth and / or in the pic rail slot as needed, with the glass bubble tube able to twist inside the housing, to put the bubble in clear view, no matter if it's sitting on a rail tooth or in a rail slot. But then up goes the price.