About the Saris Basic Mag Trainer Whether you\\\'re training for a local charity ride or working to beat your friend\\\'s Fit Bit score, the Mag indoor bike trainer can help you make it happen. Simply connect the trainer to the rear wheel of your bike, hop on and pedal away. Plus, the Mag comes with five adjustable levels of resistance so you can adapt every ride to your liking. Key Features: > Magnetic resistance unit provides a quiet and frictionless ride. > Linear resistance boosts workout intensity to match each pedal stroke and gear click. > Eccentric levelling feet allow for easy adjustment on uneven surfaces. > Comes on a sturdy, foldable frame. > Adjust tyre fit to resistant unit with a convenient turn knob.