If a wheel slippage problem is something that you need to kill-off, then Halo's all new Butch-washers with their sharp cut teeth, force multiplying design and butch, non-bending, heat treated, 4mm thick steel bodies are the 'no messin' about' answer for you..Halo Butch Design Functions:- Force multiplier design increases the force applied by 30%.- (3mm grip face Vs 4.5mm nut face.)- Smooth Nut face reduces tightening torque friction. - Sharp cut teeth 'bite' into any surface to provide maximum grip.Tech:- 4mm thick hardened Cr-Mo steel body (resists bending.) - 10.2mm clearance hole (fits 3/8" and 10mm axles) - 20mm outer diameter grip-face (fits into most dropouts.) - Black Oxide finish (suits most applications)