ReVo Leveler - RV Level - Easy to see and use leveling aid for your travel trailer. No guessing, no frustration and no trial and error. Get Level the first time. 5th Wheel and Bumper Pull trailers. ReVo Leveler can be used on Bumper Pull Travel Trailers and 5th Wheel Trailers Will tell you what board thickness (inches or centimeters) and which side needs raised to be level left to right Digital readout to display board thickness and jack extension Arrows show direction of travel to level left to right, disconnect, level front to back, and connect Can be used on the left or right side of the trailer