The VLTOR CASV-M relies on "piggy-back" mounting to the top of a “flat-top” M4 or M16A4 upper receiver. This chassis features a removable lower handguard, which allows the access of an M203 grenade launcher. The smooth body construction allows multiple rail mounting points, adaptable to any mission needs. Each CASV kit features various length removable rails and mounting hardware.  The CASV-M is the same as the CASV-EL, but with an enclosed top-end (not cut for a Carbine Length Gas System/Fixed Sight Tower). The CASV-M is intended to be a “drop-on” rail system for a “mid-length” gas system which is equipped with a fixed sight-tower/gas block system. The CASV-M can fit over a carbine length gas system, as long as a “low-profile” gas block is installed.  Like all CASVs, the CASV-M relies on the use of on the Delta Ring for a more secure mounting point. Vltor does not recommend that any CASV handguard be usedwithout the standard Delta Ring assembly.  This CASV chassis is made entirely of aluminum with exception to the stainless steel mounting hardware. After mounted, the CASV-M adds less than 1lb (14.3 oz /406g, without mounted rail sections) to the firearm's overall weight and features a QD sling swivel socket on the left and right sides.  Like the CASV-EL, the CASV-M is offered in the following colors: Black, Foliage Green and Flat Dark Earth (tan). Made in the USA.  MSRP $239.95