Great tube for braces - Tacfire AR15 Pistol Buffer Tube

I ordered this tube to mount a pistol brace. The Shockwave Blade is a bit oversized for this tube. Or the tube is a bit undersized. Either way, if you dimple the tube it works great. It threads right into the lower thread pattern and even has a notch to locate on the buffer detent. Also, this one WILL accept a castle nut. I've heard other versions have a shoulders that go right up to the back of the lower receiver and leave no room for a castle nut, thereby leaving it vulnerable to loosening from shooting. The tube came with the foam/rubber sleeve, but I'm trying to find some other use for it. Obviously this is not on the expensive side (although, I think any more than $5 for an aluminum tube with threading is absolute robbery), but it works. Haven't shot it on an AR platform but I'm sure it has no issues. I put it on a vector SDP. Thanks ATF.