Drop-in, precision-adjustable buttstock especially designed for the HK G3/91 rifle and its variants * Designed to offer the fine-tuned, customized feel of a precision target stock, the PRS is adjustable for both comb height and length-of-pull * Machined aluminum adjustment knobs feature positive-locking click detents to maintain position under recoil and allows easy, tool-less adjustments by simply rotating the knobs * Made in USA * Aluminum butt-plate and alloy steel adjustment shafts provide stability and strength to withstand severe impact conditions