Tiger Rock AR10 308 Collapsible Stock Buffer 3.8 oz Short Version Black. 308 buffer serves two purposes. First it acts as a hold over for an AR10 .308 collapsible stock. Second it acts as a buffer for your AR10 when you want to remove the buffer from the upper receiver. The AR buffer should aid in breaking in your shoulder so that you don't have to remove and replace the buffer as often. The shorter version should fit in your pocket so that you can take and shoot with it. There's not a whole lot of buffer out there so make sure you keep a couple of them handy at all times. Second the AR10 .308 buffer is one of the more inexpensive ones you can find so you can grab it on your next trip to the range. You won't find a better deal anywhere. Specifications for Tiger Rock AR10 308 Collapsible Stock Buffer Short Version: Manufacturer: Tiger Rock Condition: New Package Contents: Tiger Rock AR10 308 Collapsible Stock Buffer Short Version Tiger Rock B38: AR10 308 Collapsible Stock Buffer -3.8 OZ Short Version (BLACK) Black