Fifth Wheel Trailer Hitch Pin Box; Air Ride ™; King Pin Coupler; 21000 Pound Gross Weight Capacity; M19 Air-Ride Pin Box; Replaces Lippert 1116 Pin Box Trailair® introduced air ride technology that would revolutionize the RV industry. Since then, many pin boxes have come and gone, but the Air Ride still stands tall as the leader in air ride technology. The Trailair Air Ride Pin Box acts as a buffer between the tow vehicle and RV, arresting the impact of road shock and stabilizing the towing performance. How? Simple - the unique scissor action allows the air bag to absorb road shock and vibration while the gas shock handles the rebound or bounce effect giving RVers a better, more smooth ride. Type: Air-Ride Coupler Type: King Pin Gross Weight Capacity: 21000 Pound Length: 22-7/16 Inch Width: 12-1/2 Inch Bolt Pattern: 3 Row Horizontal Mounting Bolt Spacing: 8-3/4 Inch Vertical Mounting Bolt Spacing: 2-1/2 Inch Color/ Finish: Black Powder Coated Material: Steel With King Pin: Yes With King Turret: No With King Pin Locking Wedge: No With Turret: No With Spacers: No