Max. Door Weight: 90 kg Max. Door Thickness: 33-50 mm features: Marathon S3 door slide Maximum door width 750-900 mm Can be used with Marathon Fire Door Kit: 18950 Operation when used with Marathon fire door kit, 18950: The easily operated sliding door is returned automatically to the closed position after each operation by the smooth operation of the counterbalance weights Runs on ball bearings Contents of complete set: Top assembly (track, hanger plates, ball cage and runner bar) 2 nylon top plates (with integral buffer) Wall mounted stops Nylon floor guide (guide channel to be mortised into door bottom rail)