Fulterer FR 5400, 50 inch heavy duty drawer slides (550 lb. Class). This 450″ model has a weight capacity of 396 lbs. or 180 kg..
This Heavy Duty Drawer Guide is made of zinc plated, cold rolled steel and have a 3/4″ installation width. They have stainless steel ball bearings and plastic ball spacers to reduce friction. This is a non-detachable slide. Price is per pair, screws not included.