Use this 60 mm trailer jack wheel with a split clamp to stabilise your trailer, or to assist in lowering your coupling onto a tow ball. Durable material: The wheel trailer is made of galvanised steel, which makes it resistant to rust and weather. Adjustable design: This car jack can be adjusted to a maximum height of 87.5 cm and a minimum of 63 cm, more than enough to help detach couplings or lower them onto most tow balls. Solid rubber wheel: The solid rubber wheel allows you to move the tool around your trailer easily when the trailer jack wheel is attached. Practical clamp: The clamp is equipped with a rubber grip on the end of the handle for easier manoeuvring. It opens to allow quick and easy removal of the support frame and wheel. Material: Galvanised steel Overall size: (63-87.5) x 32 cm (L x W) Wheel diameter: 21.5 x 6.