It allows to limit the opening of the sash, thus performing a safety function. It is commonly used on casement windows and doors, but it can be also installed on outward opening, arch-shaped and out of square frames. The most significant new feature is that in the limited opening setting, it is possible to lock the sash permanently, bringing the handle in the closing position. If combined with a cremone handle with selector, it is a cheap alternative to the traditional tilt before turn system.
Fixing and sliding elements are in galzanized zamak, lever and screws are in stainless steel. Each package includes a dowel for the changeover from left to right hand and a key to unlock the stainless steel lever.