The extension set aluminium keeper, also called a connector set, includes one plate with screws and an Allen key. Slide the plate into the designated track and slide the loose parts of the profile together. After the loose parts have been pushed together, tighten the screws with the Allen key provided. As the hex screw is screwed directly into the profile, it may slightly damage the inside of the frame.
Alternative: extension set heavy
Prefer not to attach it directly to the frame? Then choose the extension set heavy. This set comes with an extra part, namely a blind plate. This can be attached to the other plate to form a complete and sturdy set.