Equal-i-zer 88004500 4" Fast-Way Flip Jack Foot Automatic Jack Foot Gets Rid Of The Hassle Of Placing Blocks Under Tongue Jack Spacer Ring And Mounting Hardware Included Bolts Quickly And Easily To The Existing Jack. Gives An Automatic 4 Inch Extension That Locks Into Place When Extended, And Folds Up Out Of The Way When Retracted Limited 90 Day Warranty