Dayco's Automatic Belt Tensioner features a patented "flat spring" design that's engineered to provide less operating range variations in tension. This reduces the risk of premature accessory bearing failure due to high tension when a new belt is installed.

It also lessens the risk of belt squeal and slippage, or poor accessory performance caused by low tension after the belt begins to stretch and wear. A Teflon® strip wound within the spring resists abrasion. The flat spring itself is coated to resist rust.