Add a back hook to the original paper clip, so that it can be used on desks with aluminum profile guide grooves in the office.

The length is 25mm, and the back hook can use elasticity to clamp the aluminum profile guide groove. When pushing up the paper and flat items that need to be clamped, the clamp itself will not be knocked off, and it can clamp about 1 to 15 A4 papers at the same time.