NF type non-contact backstop is a high-speed anti reverse device that has the advantages of reliable backstop, no jamming during release operation, large backstop torque, light weight, and easy installation. Its comprehensive mechanical performance is significantly better than other backstop devices. The internal structure adopts a new type of optimized shaped wedge block, which not only has high impact resistance and reverse torque, but also cleverly utilizes the centrifugal force of its own rotation: when the forward rotation speed of the input shaft is higher than the minimum speed, the internal work of the reverse stopper can achieve non-contact, zero wear, and a long service life. Widely used in belt conveyors, bucket elevators, scraper conveyors, and other equipment with reverse requirements.