These are the 4mm Flange Lock Nuts from Arrma. FEATURES: Steel construction Used on the Arrma Raider, Fury, ADX-10, Vortex, Granite and Fury to hold the wheels to the hub carriers INCLUDES: Four 4mm Flange Lock Nuts REQUIRES: 7mm nut driver, DTXR0216 jxs 11/10/11 ir/jxs