Works well with Blackhorn 209 Pyrodex® Pellets and loose powder! A unique knurled head requires no tools for easy removal in just 3 full rotations. It incorporates a built in 209 holder. The flat face and heavy duty O-ring provide reliable ignition and reduced blow back. The Accelerator Breech Plug? fits Pursuit? II Pursuit? Ultralight Vortek? Vortek? Ultralight and Buckstalker? Accelerator models.