"608' Version: 1x UM2 FG 608 Bracket 1x UM2 FG 608 Wheel Female 1x UM2 FG 608 Wheel Male 1x UM2 FG Mounting Nut 1x UM2 FG Plug 1x M4 Screw 40mm Long (http://www.boltdepot.com/Product-details.aspx?product=6630) 1x M4 Washer ‘626’ Version: 1x UM2 FG 626 Bracket 1x UM2 FG 626 Wheel Female 1x UM2 FG 626 Wheel Male 1x UM2 FG Mounting Nut 1x UM2 FG Plug 1x M4 Screw 40mm Long (http://www.boltdepot.com/Product-Details.aspx?product=6630) (Head of screw will most likely be large enough to make the washer unnecessary)