Detroit Locker for Ford 10.25" and 10.5" full float differential. The Detroit Locker provides maximum traction for off-road or racing use. The heavy-duty case and internals provide a dramatic increase in strength while giving 100% torque to both tires. The mechanically-operated unit works by locking while under power and unlocking when you let off the gas, allowing you to turn. Unit comes standard with a one year warranty against workmanship defects.