The swing-back bolt-on trailer jack is painted with Zinc, which is corrosion resistant. The height is adjustable from 10-1/2" to 20-1/2". Fits trailer tongues 3" to 5" and helps easily raise and lower any trailer up-to a 1/2 ton (1,000 lb) capacity. Equipped with a sturdy 6" wheel that provides low-friction mobility, allowing you to move your trailer into position easily. Convenient wind handle delivers fast, smooth cranking