The new Hustler Super Z HD I bought last spring came with a Grammer air suspension seat. I have some rough lawn and the air seat is a lot better than the spring suspension seat I installed on my old Hustler Z. I have chronic lower back problems and the air seat really helps. Many zero turn mowers have a common seat mounting bolt pattern, so a replacement seat is a bolt on install. The air seats are expensive, but to me very worth it if you have rough ground. Vic