The Genius model can be chain driven or spring operated, or a chain and spring combination. Bottom bar catches can be external / adjustable or concealed fixed type. Model with fitted brake available only on the spring operated version. Photo 2 above shows spring and chain version model fitted with face fix accessory kit. Photo 3 shows a very wide screen which requires extra support in the centre, additional spring clip fixings will be supplied as required.All models can be easily fitted within the window reveal or on the face of existing window frame or wall. See diagram below for dimensions of this system.