These are our new air brake/parking brake lockout blocks that protect our RV's from a accidental rollaway if the knob is accidently hit/pushed by our kiddos or pets. They simply slide under the knob/lever, click and lock. When purchasing just tell us what color you'd like and which size you would like the Original or Mini and we'll ship them right out to you. The Original measure 1.8 L X 1.693 W X 1.15 H and the Mini measures L 1.8 X W 1.693 X H .697. Secure your brakes, secure your peace of mind
