The 37.27 limit device  hardware is designed to restrict the opening on projected or casement windows. This mechanism automatically stops the vent at a safety position as required by the user, or required by law

This Truth Limit Device is designed to restrict the opening on projected or casement windows. When properly installed and operated, the limit device will prevent damage to casement and awning windows under high winds in high-rise applications. This limit device is used by several window manufacturers.

Limit Device with key released feature.

Limit Device Key (#16002) sold separately (see related product below)

See attached spec sheet for more details about opening degrees position

Screws included:

2 pieces of #7 x .720 Philips, Pan Head, Steel Sheet Metal Screws and 2 pieces of #7 x .750 Phillips, Pan Head, Stainless Steel Sheet Metal Screws.