Hi, I recommended this before to you. It is what I used. You can pick what coarseness you want from the options on the page. They have 3 options to pick from, the over 40 gallon one is the coarsest.
Filter Max III Foam Sponge Prefilter for Aquariums up to 40 Gallons
The above suggestion has different inserts to fit the end of the pipe and will place the prefilter away from the glass too.
Aquarium co-op has filter inserts that will slip over your intake too.
Cover the intake of a hang-on-back (HOB) or canister filter with a pre-filter sponge to stop small fish, snails, and debris from clogging the filter motor.
www.aquariumcoop.com