The New Kwaiback MK6 is at Dealers Now!
Cammed head for anti-spin in frame, offset is .003 from center
Barrel: .2495 dia x .485 long
Head is .475
Hex is 3/32nd
Will fit any Hoback Knives from 2013 on, and some Hoback Knives from late 2012, except the MK Ultra and OSF.