A.R.M.S.® #36™ Ex OSR SWAN® Sleeve
Optical Sight Rail 5.56 cal. 8.46″ long. 100% MADE IN THE USA.
Designed for those who want optimum optic accuracy without the need of combat built-in iron sights, but need the other capabilities as found on the #38™ Ex Military Swan® Sleeve. This OSR(Optical Sight Rail) slides over the receiver from the rear of the weapon and extends 8.46″. It raises the rail by 1/2″ while protecting the rifle dovetail rail. Developed in 1998 and released in 1999. US Patent No. 5,142,806.