These silicone end caps are used for re-sealing water resistance LED strip lights that have been cut to a custom length. Easy use for LED RGB Flexible Strip. White Silicone design helps give it a hidden invisible look while not obstructing light from the strip. End cap is 13mm length and will fit RGB LED Strip lights and so on. They are commonly used to re-seal and re-waterproof LED strips after cutting or resizing them.