The whole lock is formed by a quenched high-carbon steel U-rod and a thickened alloy lock body. The appearance is as simple as a horseshoe, but it can bite the disc or spokes in an instant, forming a “steel threshold” visible to the naked eye.The lock core adopts a double-row marbles + serpentine key slot design, which is anti-prying, anti-pulling, and anti-opening; the surface is sprayed with environmentally friendly nano-paint, which is scratch-resistant and rust-proof, and does not fade in the sun and rain.It is intimate that a soft rubber sheath is embedded on the inside of the lock beam to avoid scratching the wheels or shock absorption; some models come with retractable mounting brackets, which become “car-mounted pendants” in seconds, so that they will no longer dangle during riding.It is not large in size و moderate in weight, and can be easily stuffed into the seat bucket or tail bag.A reliable U lock is the confidence of the knight when he leaves the car: stop, lock, and leave in three seconds.