Park tool chainring nut wrench cnw2the cnw 2 makes chainring bolt set installation and removal easy it securely holds the slotted nut to prevent spinning when tightening or loosening the bolt double ended to fit most slotted type nuts including the campagnolo chainring nuts features double ended to fit most slotted type nuts the outer width of both ends of the cnw 2 are nominally 12mm wide one end has a two outer tips nominally 27mm wide each and the other end has tips of 38mm each the