The Maco Rail Espag 20mm is designed for BS7950 security windows and has 7.7mm mushrooms. The reverse action operation pulls the cams together, clamping them into both sides of the striker plate for strength and security. It uses the existing range of Maco striker plates and is suitable for all types of euro grooved profiles making it ideal for use not only on PVC profile systems but also Timber and Aluminium.