Recessed wheels for the Glider sliding door system. It has a pair of upper wheels and a lower pair, made of black plastic and with a metal bolt axle. They can support up to 20 kg of weight and allow the height to be adjusted by reducing it by a maximum of 1.5 mm or increasing it up to 4 mm. The mounting and machining system is the same for both pairs of wheels. To install them, it is necessary to make a U-cut for each wheel, 11 mm deep, with a 35 mm diameter drill. After stuffing it, the plate is screwed to the door with 4 self-tapping screws. The packaging contains 10 units.