"Evo Pro" Series Trotter The "Evo Pro" Series slat mills are our top of the line Treadmills. They have everything you need to put a dog in top notch physical condition. All "Evo Pro" Series mills include the following: All Aluminum hinged 2 piece Frame with 4" elevation adjustment.   Dual track shock absorbers. Accubrake. 12 Function Digital Speedometer Anti Skid Composite Slat Trck 8" Dolly Wheels. Sealed Precision Free spinning bearings. Heavy Duty Axles and bearing setup with 1 25" aluminum axles. Fully adjustable tracking system. Fully adjustable tethering system. Backed by our two year axle to axle warranty. About Size