Shark HV380 Rocket DuoClean...
$6.99
Product details
Shark's Rocket DuoClean sticks keep a foam filter ahead of the motor, and F668 replaces it in the HV380 and its siblings, the HV381, HV382, HV383 and HV384Q.
Foam is the first stage after the dust cup, and on a machine this small the filter area is tiny. Once the foam packs with fine dust the Rocket makes plenty of noise without picking anything up, and the motor runs hot because it is starved of air. Foam that has torn or gone permanently flat fails the other way, letting grit straight past to the motor.
Rinse it in warm water monthly, dry it fully, and put it back the same way around. Once it will not spring back to shape after drying, or it has thinned at the edges, fit a fresh one.

