U-BOLT, 2 3/8" RD 1/2"-20 x 5 1/2" and Two Nuts.

Redline Trailer Suspension Parts - SP01-040
U-Bolts
Camper
Car Hauler
Utility Trailer
Round Axle - 2-3/8 Inch
5-1/2 Inch Long
3500 lbs
1/2 Inch Diameter
Redline

Round Trailer U-Bolt
2-3/8" Wide
1/2" Diameter
5-1/2" Long
Includes Lock Nuts
Torque:
Minimum: 45 foot lbs
Maximum: 70 foot lbs