Ideal Tilt Reading - Each gauge monitors tilt from -10 to 10 degrees. Brass ball rides in special damping fluid for smooth, accurate leveler readings. Easy to Read Display - Brass ball indicators in bright Saturn yellow tube assembly provide higher visibility than traditional bubble levels. Engraved and hand painted numbers make for a functional, easy-to-read display. Shatterproof Design - Slope indicator tube assembly is made out of a rugged copolymer "flex tube" for ultimate durability. Can be mounted on the inside or outside of RV, camper, or popup trailer. Mounts With 3M VHB Tape - The levels includes a piece of 3M VHB (Very-High Bond) adhesive tape on the back for easy stick on mounting. Also includes two guide holes for screw mounting. Pair with leveling blocks for a full camping trailer leveling system. Made in USA - From durable, high-quality materials. Lev-o-gage slope indicators are built to last. One of the must-have accessories for RVs, campers, travel trailers, 5th wheel, tractor, truck, car, boat, or any vehicle that tilts.