- For other uses, see Thumper.
- "An improved long barrel for an infantry-carried grenade launcher. Fires projectiles at higher velocities and distances. Compatible with a wider variety of launcher projectiles."
- — In-game description
The JAK Thumper-656 is a conversion kit for the RGL-80 grenade launcher featured in Call of Duty: Modern Warfare III as part of the Aftermarket Parts system. It was added as part of the Season Four update.
It changes the RGL-80's scope into a red dot sight, applies the SL Skeletal Vertical Grip on it, and allows the RGL-80 to use different types of ammunition. In addition to the standard impact grenades, it can fire 40mm Slugs, Sticky grenades, and Drill Charges.