Cockspur handles are often found on older type windows which do not have an internal mechanism ( a small square drive that can be seen if you remove the handle) to secure the window; cockspurs are also found on windows which have a slim frame such as caravans or mobile homes. The handle locks by means of a spur (little triangle bit) pulling up against a plastic wedge that is found on the window frame. As a general rule Aluminium window frames use a 9mm handle and UPVC frames tend to use a 21mm handle but this is not always the case and many other sizes are made.
The important measurement needed is the stack height which is the distance from the base of the handle to the underside of the spur, if you're not sure how to measure this click here to see a picture showing the stack height. or click here to watch a video on how to measure your cockspur handle
The wedges on your frame come in various different sizes starting at 2mm thick going up to 8mm thick. We sell all the differant sizes and they are available in Black and White