My Trailer Aid weighs about 10 lbs and is a plastic/rubber material that water can't hurt. I can change a tire in approx 15 min and my knees [much less my body] never touch the ground.
The "Wedge" idea is sooo simple and safe. If you have two or more axles, it is the way to go.
2013 Silverado 2500 HD Duramax/Allison Tuned
Aviator Wright Flyer #1919
"First In, Last Out". 11B4Y
DAV, MOPH, VFW, 5/7 Cav,1/8 Cav Assoc.
11th ABN Pathfinder Co. N7MIP