MAGPULA(R) UCS(TM) ADJUSTABLE CARBINE STOCK FOR AR-15 The Magpul UCS (Universal Carbine Stock) is designed to be the ideal supplement to the vast array of firearms utilizing a vertical M1913 Picatinny rail on the rear of the receiver for stock fitment. To accommodate the wide variety of charging handles styles, ejection port locations, and control locations, the UCS features a reversible hinge for left and right folding configurations, and five degrees of drop for clearance. The UCS ships with two reversible Cheek Risers (0.50'''', and 0.75''''), and when combined with the reversible M1913 clamp (allowing for a 1/2-slot height adjustment), the shooter can dial Mfg: Magpul