We have these sliders on our country trailer (SUV jeep). They are used to hold our trailer's power system. (Battery, charger, inverter, battery breaker, fuse box and cable.) These sliders hold up well and carry the weight very well. It's nice to have when we can turn off the power system and check fuses, charger and everything. and then push back into the trailer and drive on. You can take out the sliders, but it's a bit difficult to get them back. But once inserted, they slide perfectly.