Cat Flap Mosquito Screen

Add the brass heat inserts to the bottom frame

by putting some Superglue to the outside channel on the bottom frame, glue it to your mosquitto screen. The glue provides also an extra layer of security. 

Add glue only to the outside channel and make sure you won't get the glue somewhere else, otherwise you may not be able to provide enough clamping pressure when screwing the top frame anymore.

Screw on the top frame. Make sure it is really tight!

Cut the remaining screen in the inside.

make sure you free the link from the screen

cut the cutout screen to size and glue it to one half of the flap

Glue the two flap halfes together

and install it with the two doorholder parts.