Wheel Masters Level Master all-in-one RV level provides visual side-to-side and front-to-rear leveling assistance for trailers, 5th wheels and motorhomes. Level Master can be viewed from the driver's seat to help locate the best level location for parking your RV. Each mark on the side-to-side scale indicates one inch of blocking. The front-to-rear scale is adjustable and can be easily viewed while operating your tongue jack.