Whitco Chain Window Winder MK8 W380217 Black D5 Key Lockable Keyed AlikeFeatures: Smooth operation Through flyscreen operation Push button to lock, key to unlock opening versions also available, please see our store)Suits aluminium or timber awning windows with butt or hook hinges, or non friction staysLess than 1 mm between locking pointsMaximum opening 300 mm, 19 handle turns to fully open (RestrictedCan be wound closed when lockedHooded sash bracket prevents chain being dis engaged from sashStandard and one way fixing