A multi-function trailer hitch lock and general purpose two piece U-shaped shackle lock has three components. An upper component is an upside down U-shaped shackle having at least one leg with locking grooves. For trailer use to engage the recess in the trailer coupler, a platform with a ball is slid up the U-shaped shackle legs. The third component is a separate locking assembly that is slid up the U-shaped shackle legs. This third component has a rotatable lock mechanism to drive a cam based latch mechanism between a latch state with the locking grooves, and an unlatch state. For general use such as locking a bicycle tire to a bike stand, the platform component is removed.