Keys treadmill models perform quite well and will help you achieve your fitness goals

Regarded as relatively new in the fitness industry, Keys treadmills fitness program began in 1977 with their low priced schemes. Keys treadmill have already built an extraordinary and broad product range of low to mid-price discount in the market within a very short span of time.

Keys treadmill possess some seven impressive series of treadmills like Alliance Fitness, Milestone, Health Trainer, Discovery, Keys Conventional, Encore and Pro series and also a few folding for those who do not have enough space

The Magnificent 7
Alliance Fitness Series: These are high quality Keys treadmill for professionals. The motor sizes range from 2.5 hp to 3.0 hp. There is a 10 years warranty on the motor and lifetime coverage on the frame. 
Milestone Series: Milestone treadmills feature more reviews. The motor range is 2.0 hp - 2.5 hp with 10 years warranty on all models.
Pro Series: Do not go by the name. These are the lowest priced treadmills. The motor size is under 2.0 hp the warranty is 1-2 years cover on parts.
Conventional Series: These treadmills are non-folding and built to last and cover a 10-year warranty on all motors.
Encore Series/ Discovery Series/ Health Trainer Series: There is hardly a clear difference between these series. Motor sizes range from 2.0 hp to 3.25 hp and 10 years warranty on all motors.