Kryptonite Gravity WheelNutz Gravity locking system that secures to your front wheel Easy installation - only requires a 15mm wrench (No keys) WheelNutz provide internal lock-out function and can only be removed by turning the bike upside down 180 degrees Use in tandem with Messenger Mini to create a complete locking solution for your bike Weather protective coating keeps WheelNutz from corroding In addition to popular M9 thread - M10 (001775) and 3/8 (001782) also available Product weight: .17 lbs. (.77kgs) Only 81 grams per set