Tester: Marc Potter Miles covered/time: Used for four years What's good? It's been out in the rain for years, but with a squirt of WD40 it works a treat and has never let me down. So strong that I wheeled a GSX-R1000 backwards a foot and it smashed the disc and the front mudguard without bending the pin of the lock. It's Thatcham-approved, too, and is a brilliant deterrent, though it has never had to face the ultimate test. What's not? Nothing, just remember to hook the coiled flex over the bars to remind you it's there.