Includes spacer to allow for installation in both carbine- and rifle-length buffer tubes.
| Model | Caliber | Best For | Not Recommended For |
|---|---|---|---|
| JPSCS2-15 AR-15 |
| .223/5.56 or smaller | .300 BLK (Supersonic or suppressed w/ subsonic ammo) | 6.5 Grendel or larger (w/ low mass bolt carrier and adjustable gas block) |
| Duty/competition rifles with standard or low mass bolt carriers | 14.5 - 20" barrels | Semi-Auto |
| SBRs | High back-pressure suppressor use | Piston systems | Select-fire |
| JPSCS2-15H2 / JPSCS2-15H3 * AR-15 |
| .223/5.56 or smaller | .300 BLK (Supersonic ammo only) | 6.5 Grendel or larger (w/ standard weight bolt carrier) |
| SBRs | High back-pressure suppressor use | Piston systems | Select-fire |
| Light-weight operating systems/low mass bolt carriers |
| JPSCS2-10 AR-10 |
All | | Light-weight operating systems/low mass bolt carriers and adjustable gas block | | SBRs | High back-pressure suppressor use | Piston systems | Select-fire |
| JPSCS2-10H2 / JPSCS2-10H3 * AR-10 |
All | | SBRs | High back-pressure suppressor use | Piston systems | Select-fire |
| Light-weight operating systems/low mass bolt carriers |