EXOS Defense has released their take on the AR pistol buffer tube. Their buffer tube is designed to accept the SB-15 Brace and has a stand-off collar to increase the “length of pull”. It also features a sling swivel socket in the rear of the tube. The tube is 9.125″ long and weighs 7.2 oz. It is secured to the lower receiver via a standard end plate and castle nut.
EXOS Defense machines these from 2011 T3 Aircraft Aluminum which they say is significantly stronger than the 6061-T6 aluminum used for most pistol buffer tubes (20% Higher in Tensile Strength and 30% Higher Elongation than Standard 6061 T6). The tubes are hard anodized with a dull black matte finish.