Corrosion-resistant, surge-type actuator bolts over 3" wide trailer tongue and includes standard, heavy-duty coupler with 3" drop. Unique roller design helps reduce resistance. Application: disc brakes; Ball size: 2-5/16"; Drop: 3"; Mounting: 3" wide channel tongue; Capacity: 12,500 lbs; Maximum tongue weight: 1,250 lbs; Built in Backup Valve;