Clone of the latest version of the SHS NGRS piston.  15 teeth so you'll need to remove 1 in order to correct AOE should you need.  The SHS design suffered from the issue of the rack seperating from the body due to the rack not having enough material at the back.  To help prevent this from happening epoxy can be used.

At present I've got a small amount of these in from a supplier to try them out, the price is reflected in this.  I'm working with the manufacturer to get the design changed slightly.

Teeth Width: 4.65m
Weight = 17g
Length = 66.9mm