The RoadLoK isn't like a chunky device that designed to ONLY keep the criminals at bay, it actually LOOKS cool too. Fits permanently to your front brake caliper and simply stops the bike from moving forwards or backwards. Not only does it look great, fit great and do a great job, it doubles up as a stupidity detector. If I forget to take it off (lets face it it's always a possibility) my bike won't spit me off in half a wheels turn, it'll just STALL, which means I dont look like a prat and have an expensive repair job in my lap. Yep, its not cheap, but that one time you forget to remove it means its paid for itself in one swoop. I just wish I knew they came in loads of colour choices, as if i'd have known they did a blue one, i'd have bought it in blue, simple as that. The people I bought it from were dead helpful too. They seemed to know what they were talking about, which always helps make a decision and they had stock in the UK so it took about 2 days to arrive.