NuStep UE8 Upper Body Ergometer The Pro has an 18 inch wide seat. The Max has a 22 inch wide seat. That is the only difference between the two models. Ergometer Features Sit, stand or direct wheelchair access without removal or attachment of the seat Low starting force with 15 levels of resistance Bidirectional operation Integrated sensor technology Compatible with WellGrip accessory Ergonomically designed seat with contoured back swivel 360 degrees Seat-back recline an additional 12 degrees Supports users up to 500 lbs Ergometer Features Dual HD Touchscreen Monitor with Intuitive Software Quick Start - Get on and go Pace Partner - Stay on track with a steady pace NuStep Charts - View statistics based on performance Trail Runner - Exercise in locations around the world Balanced Power - Measure power and identify imbalances Product Specs Machine Footprint: 74"L x 32"W x 52"H (188 cm x 82 cm x 117 cm) Unit Weight: 310 lbs. (140 kg) Standard seat width: 18" (46 cm) Power: AC adapter with front and rear power jacks Warranty: 10-year frame, 3-year parts, and 1-year labor. Height: Fits users from 4'6" – 6'7" (137–200 cm) Weight: Pro Supports users up to 500 lbs. Max Supports users up to 600lbs