This is a hook to assist threading the seatbelt through the back of a car seat. The access holes on most car seats are not large enough for my hands to fit through (without forcing them through and scraping my knuckles!). Put the latch of the seat belt buckle on the hook, push the “T” end of the handle through the back of the car seat. Reach around to the other side of the seat and pull the handle through with the buckle.

I printed it with PETG because I am storing one in each of our cars. It needs to be printed with supports.