Where can I find Insect screen in Alfter?

Insect screen can also be found in these cities:

Bonn Bornheim Cologne Erftstadt Euskirchen Hürth Königswinter Niederkassel Rheinbach Rösrath Siegburg Sinzig Troisdorf Wachtberg

You can also find this in Alfter:

Answering Machine Balcony Plants Concrete Formwork Blocks Mailbox Lathes Random Orbital Sander Veneers Scaffolding Hand Basin Wood Screws