2007-2016 Twin cam models and 2018-up M8 models

HBA007A:  Stock length：62 15/16" (62.9375"); adjuster :28" ;travel:3.1"（79mm）

HBA007A-I: add+2"

HBA007A-II:add+4"

HBA007A-III:add+6"

HBA007A-IV:add+8"

HBA007A-V:add+10"