Command Arms AR15 Adjustable Buttstock Cheekpiece: * Designed to mount on the CBS collapsible stock"s Picatinny rail or PRFCS with rail for 4 existing collapsible stocks * Patent pending * Adjustable for height with thumb knob * Allows proper eye relief of scoped rifles by moving horizontal along collapsible stock * Ambidextrous design * Manufactured from durable polymer with smooth finish * Compatible with most existing AR15 carbine style buttstocks with the use of PRFCS