The LH-4000 Hydraulic Wheel Ski is for those that need the ultimate ski utility, hard surfaces and maximum performance on the snow. The LH-4000 is a thermoplastic ski incorporating some of the latest technological advances in materials making it stronger and lighter than other skis. When in the Ski position, a hydraulic cylinder drives a carbon door under the wheel, making the bottom flush on the snow. The LH-4000 performs as well or better than a straight ski, yet offers the versatility being able to use the wheels when you need them. Certified On: Cessna 180/185 & Found-Bush Haw