MAXIM DEFENSE INDUSTRIES AR-15 CQB STOCK REPLACEMENT JP SILENT CAPTURED SPRING SYSTEMS Designed for the Maxim Defense CQB Stock, the Silent Captured Springs are Maxim exclusives made by JP Rifles. By eliminating the friction found in standard buffer setups, the JP Silent Captured Spring also allows for smoother action resulting in less sound as the bolt cycles. Available in a Standard weight and a Heavy weight for select fire platforms version. JP Heavy (2 weight) is equal to a 4.0oz buffer weight JP Standard (2 weight) is equal to a 3.3oz buffer weight. Mfg: Maxim Defense Industries