Horizon T81 Treadmill Lube Belt. Lift the belt as far as you can and squirt the silicone oil in a zigzag pattern across. One bottle is good for two applications.
I use silicone based lubricant directly from the treadmill manufacturer. To keep your treadmill performing well, you need to replace the lubrication once it wears low. Damaged walking belt, improper belt tension, lack of belt lubricant, bad drive motor.