This device is designed specifically for the Mossberg 500 Persuader type 12ga. (5 + 1 with an 18.5" barrel).

It simply attaches to the Take Down Screw giving you a cost effective, breaching / standoff device.

Your Take Down Screw must be the newer version, 1" in diameter x 3/8" thick with a threaded swivel hole in the middle.

Machined from 1144 Stressproof steel and plated black and may exhibit some signature marks or imperfections. 

It will come with all assembly hardware, including a 1.0 ml package of VC3 Threadmate, and installation instructions. 

All you'll need is a phillips screwdriver. 

Dimensions are as follows:

An OAL of 4.627". A working length of 4.22" from the face of the take down screw to the tips of the teeth, and an OD of 1.250. Dimensions are approximate.