The HIIT Airbike by AirTEK fitness is a high quality commercial grade exercise bike specifically built for High intensity interval training (HIIT) but can also be used as an Aerobic stationary bike. There are no resistance knobs to mess with. The resistance is built into the bike. The faster you pedal, the harder the resistance becomes which is awesome for HIIT. The slower you pedal, the easier the resistance becomes which is excellent for aerobic training. The 25” Aero-Fan blades and fan cover are made of steel, not plastic. The seat moves up and down and also forward and backwards to put your body In perfect position for the pedals and handlebars and is poly-belt driven for a smoother, quieter ride. No chain to oil, tighten or break. The bike’s monitor has 12 built in programs. (4 target quick key HIIT programs and 4 target quick key programs such as heart rate, calories, distance and time. Can even use the manual mode for customizing your workout interval times). The bike is commercial grade quality at 157 LBS and maximum user weight of 350 LBS. the bike has only been used 3 times. This bike gives you the best of both worlds. HIIT or Steady State cardio training and is built to last for years.