Duck Head Kit: This manual tire changer duck head kit is designed for manual tire changers (not included). The mounting tube diameter is 2.4" (60 mm), compatible with manual tire changer shaft diameters ≤1.8" (48 mm), enhancing tire changing operations Fits 16"-21" Tires: Easily adjust the duck head position to adapt to tires ranging from 16" to 21" (406-533 mm). The tire changer adapter is universally suitable for tires on cars, SUVs, trucks, UTVs, ATVs, and other vehicles Reduces Rim Damage: The manual tire changer duck head is made of reinforced nylon with a grooved design, featuring no sharp edges to avoid scratching rims. It minimizes damage to your rims during operation Heavy-Duty Steel Construction: The tire changer duck head is built with thickened, heavy-duty steel. The reinforced tube walls provide high strength, withstand pressure when dismounting large tires, and resist deformation Mount & Demount Tires: Easily insert the manual tire changer into the tire and rotate it once to complete tire mounting and demounting. It includes a silver cone to enhance wheel hub stability and secure the tire changer, avoiding wobbling during use