These air bags are thick and good quality. Installation is difficult using only your hands. After unsuccessfully wrestling with air bag to place in spring for 45 minutes, I got a blunt tire tool to pry the bag into spring, this took 2 minutes. The second bag was in within minutes. Also use soapy water to lubricate everything. My rear springs are new yet still not as firm as I wanted, the air bags improved the stance and firmness (not stiff or rough) of the ride. Also nice to adjust air pressure when packing additional stuff for trips.