Abstract: A lock has a preferably generally box-shaped body and a handle joined by and formed integrally with a narrower neck. The lock is useful for removably securing, without the need for semi-permanent attachments, Christmas light strings or other objects into a track system, which can run along the exterior of a structure. The body preferably can be rectangular in cross-section with rounded corners and slanted side walls and is dimensioned such that the manually turned handle rotates the body to press snugly against the inside walls of the track in one direction and fit loosely in the other direction.