The lock nut supplied is not a lock nut. It is only screwed onto the filter. It has no steps that engage the bottom of the filter housing. So the filter doesn't stay in place. Unfortunately I didn't keep the original nut.
Pros
Effortlessly picks up sawdust, wood shavings, construction site and vehicle dirt. Material: paper cartridge. Corrugated cardboard creates a large surface replacement for the effective removal of dust and dirt and is easily cleaned and easily installed.