OnGuard Pitbull DT 8005 Large U-Lock - Sold Secure DiamondOnGuard Pitbull DT 8005 Large U Lock Sold Secure Diamond The OnGuard Pitbull DT U lock bike lock is accredited with insurance friendly Dimanod Sold Secure. This is the highest protection rating that a bike lock can achieve. It is rare to see such a solid quality bike lock at this price that can offer such protection. This lock offers ultra high protection so you can be sure that your bike is safe and secure. It is designed for use in medium to high