The Mesa Tactical Sureshell Shotshell carrier for the M4 Collapsible stock is a lightweight aluminum shell carrier designed to mount on the right side of the stock body, but can also mount on the left. Constructed with 6061-T6 aircraft aluminum and mil-spec anodized in matte black. The shell holders feature a neoprene friction retention system to hold shells securely for years of use. The Sureshell carrier is mounted with an included backer plate and fasteners. Uses integrated sling slot in stock (new hardware included).