For those looking for a low-impact exercise that is still effective in building cardio, the Air Walkers (Gazelle) with Cylinder and 3 Resistance Levels (Light, Medium, and Heavy) are an excellent choice. They are also a fantastic choice for those looking to increase their muscle mass or stamina. Mpulse Screen Digital Meter Brand Goal Initiative No knee strain Level 3 resistance User Weight Maximum: 100 kg Foldable dimensions: L 110 cm x W 10 cm x H 140 cm; net/gross weight: 24.3/22.3 KG; dimensions: L 100 cm x W 71 cm x H 140 cm