You will need to measure Backset minus the rebate. (the space where the door sits in the frame).
To install the locks, you need to measure from the center of the keyhole to the closest edge of the door frame. This is called the backset minus the rebate (the space where the door sits in the frame).
- For the SF model, you need this measurement to be 30mm.
- For the EF model, it should be 25mm
- For the BF model, it should be 25 mm
- For the CF model, it should be 35mm
