The opening cards are manufactured out of high-flexible plastic, fit in the fold of the door and allow to slip the latch.
The Door Latch Opening Cards are made from a type of plastic specifically created for their use. They allow a fast and easy opening of doors that are “only” closed, but not locked. Especially in cases where the gap between door and frame is too narrow for the use of Door Latch Needles these cards can prove their usefulness.