Is there a product that sits in the channels in the extrusion, rather than unsightly and cumbersome surface mount? I've seen the round flush contacts but they look too chunky and are probably intended for wooden frames.
have just measured the channel in the extrusion - it's approx 12x12mm. the frames are Rehau and I believe there's a steel core/liner so drilling would be a tricky affair..It depends on the gap available. Sometimes you can get the magnet of a standard surface contact into the groove of the opening part and there will be room for the surface contact in the gap between the opener and the fixed frame, like this:
View attachment 341620View attachment 341621
Experiment with some double sided tape to hold things in place before drilling any holes.
You might need to shave a little bit off the sides of the groove with a Stanley knife to get the magnet in, often there is a little ridge on the sides of the groove which just makes it too narrow for the magnet.I have ordered a pair of CQR magnets and contacts that are 13 x13mm and will experiment with how they fit..