Frame engaging adapters are ideal for lifting vehicles such as pickup trucks with frames. They provide direct contact to frames without the slipping associated when lifting on slippery, sprayed undercoatings with traditional rubber pads. Cradle provides a secure fit to frame in tight spaces. Works with all Challenger above ground two post lifts. 15,000 lb. capacity inground lifts require reducer busing kit part #10317. Sold as a set of four.