Machined from solid 7075 T6 Aluminum Billet. Complete with larger ejection port, standard picatinny rail, includes fully chrome bolt carrier group (gas key, cam pin, firing pin) and stainless steel charging handle assembly. The LAR OPS-4 side charged uppers comes in left, right, and ambidextrous models. The charging handle is reciprocating allowing for both the charging of weapon and forward assist. The LAR OPS-4 upper is designed to hold much tighter tolerances for match shooting making this upper the most durable and accurate upper on the market.