Designed for First Strike Round use, the Rifled PWR Inserts - manufactured exclusively in the USA by Lapco Paintball - are the perfect accompaniment to the Eclipse S63 Barrel System, for those looking to maximize the performance of FSR and other shaped rounds. > Rifled for accuracy. Threaded for security. Engineered to perfection. The Rifled PWR Insert incorporates a unique threaded section which secures the insert into the tactical back section and prevents rotational movement when the FSR is fired. This creates a stable environment for a more consistent and accurate shot. Available in two bore sizes, 0.686 and 0.683, these precision-machined rifled inserts allow the player to accurately match the rifled bore with the batch of First Strike Rounds for supreme performance. FEATURES + Eclipse Rifled PWR Insert+ Manufactured in the USA by Lapco+ 8.5 Length+ Threaded Locking System