Great concept - Strike Industries AR Optimus Weight Recoil Buffer

Great having the 4 weights to mix n match instead of 3. Not all aftermarket weights will work with this buffer. I have 2 S.I and 2 Odin works adjustable buffers. Odin works weights are just a hair to big in diameter. Also a couple other buffers from guns I've changed the buffers in are the same way I think I've had one out of several buffers that I could rob the weights out of and fit in the S.I adjustable buffer. Seems like the buffer will not fit in S.I flat wire springs either. But I'm not a 100% on that. I am 100% Odin works buffers will not fit in the S.I FLAT WIRE SPRING.