Keep your rifle in tiptop condition to maximize its full potential with this replacement bolt assembly from Umarex. Constructed fully from metal, this bolt assembly is highly durable against intense internal pressure during rapid fire. This self contained bolt unit is specifically designed to be used in T4E TM-4 and H&K 416 .43 caliber Co2 paintball rifles from Umarex. The simple design makes for a quick and easy installation done at home. Bring your rifle back to like-new condition by adding this new replacement bolt assembly into your lowdown.