These light-duty endstops are designed to keep cars from coming off the end of the track; a stopper knot in the purchase system to prevent the car slamming into the endstop is recommended as these are not engineered to handle repeated shock loads from a car slamming into them.
These “ESP style” end-stops are typically only used as OEM equipment supplied to boatbuilders that install a Harken track system. For retail consumers, we recommend the standard (red) endstops, or the Heavy-Duty endstops held in place with two screws, which are designed to handle shock loads. Use with Harken track 27mm low-beam track.