Motors need to be protected from dust and dirt entering them. It is crucial that only clean air is taken into the motors. This protects any buildup of dust and dirt on the fan blades increasing the life of the motor. This buildup blocks the fans from flowing air properly and greatly dimenishes performance of your vacuum system, not to mention leading to motor failure.

Ametek Lamb specifically states in their warranty information that "typical signs of abuse inludes dirty motors, failure of which was (or is) caused by inadequate filtration will NOT be considered in-warranty failures". In other words, it is required to adequately protect the fan blades of the motor from dirt and debris or risk being out of warranty.

Just place the motor filter on the bottom (the fan side which is the widest part) of the motor with the black filter side facing down. Then place your motor and the filter on to your motor gasket. Secure the motor as required.

Protect your motor so it provides you with many years of trouble free service!

Only to be used on 5.7 inch motors! Not for 4.8 or 7.2 inch motors.