- STEP 1 Open the window and measure a gap of 100mm, or 89mm if there are children around.
- STEP 2 Position the restrictor on the opposite end from the hinge until the cable is tight, then mark the area for your pilot holes.
- STEP 3 Drill your pilot holes using a 2mm drill bit and a drill.
- STEP 4 Close the window and screw each plate of the restrictor in place.
Note: If you are installing a keyed or keyless restrictor, the keyhole or twist lock should not be on the open part of the window.