I purposely wanted a lock with small inner dimensions to minimize air space inside the lock and deter against prying attacks. This lock is exactly what I was looking for and is big enough to fit around my bike frame and bike racks/parking meters/posts in San Francisco while leaving a minimal amount of air space inside the lock. Haven't had the lock tested yet luckily but it seems to be made of high quality materials with good craftmanship. Also extremely light for a gold-rated lock. I did a fair amount of research on bike locks after having my last bike stolen using a pry attack against my u-lock and settled on the seatylock plus hexlox for my wheels.