BIG WHEEL ATTACHMENT Our Big Wheel Attachment is designed to allow you to tilt back your dolly, resting all 4 wheels on the ground, alleviating most of the weight of the load you are moving. Works great when moving heavy loads over uneven and rough surfaces like gravel, dirt or grass. It works by clamping on to the back of the Dollies I-beam frame, using a turn buckle (hand tighten only) to loosen and tighten. Only works with Yeats Dollies!