This upper receiver armorer’s block will allow the gunsmith or enthusiast to assemble, modify, or maintain most AR pattern modern sporting rifles. While most blocks will only fit one specific style, the XS Universal block provides the versatility need to work on any AR pattern upper receiver: AR-15, AR-10, SR25, or DMPS GII. This versatility, plus the reliability of an XS Sights Made in the USA aluminum product, is a one size fits all solution. Mfg: Xs Sight Systems
