uPVC Window Handle Inline Replacement uPVC Window Handle Key-locking push-button in-line window handle for use with espagnolette and shootbolt window locks (a spindle protrudes from the back of the handle). The push-button enhances the security of your window by keeping the handle in a hold position even without the key. This feature will avoid the handle being flicked open from the outside, even when unlocked by the key, via a long thin screw driver between the frames - a common security attack! Operation of the handle is achieved by simply pushing the button and opening to a holding position. The handle will automatically re-locate to a locked position upon closure. The key supplied will provide a deadlock to the cylinder.