The SVFL01 Frameless Flat Roof Window is designed to let the maximum amount of natural light into your space, with the minimum of fuss. Skylight Internal Size Guide All size guidance is based on the use of the provided Easy Fit Timber Kerb. The measurement we give is the internal kerb size. When installing your skylight this should be the same as the inside structural opening size / hole in your roof size. For example, if purchasing a 500mm x 500mm skylight, your inside structural opening size should be exactly 500mm x 500mm. Key Features: Triple-glazed toughened glass (6-16-4-16-4) with Low E soft coat Self-clean coating on the outer pane* Includes Easy Fit Rebated Kerb for simple installation Thermal transmittance value (U-value) of 0.8 W/m2K (centre-pane). Modern black border with seamless glass design Glass Specification: Outer Pane: 6mm Toughened Clear Glass, Self-Clean Warm Edge Spacer 1: 16mm Cavity, 90% Argon Centre Pane: 4mm Toughened Clear, Soft Coat Low-E Glass Warm Edge Spacer 2: 16mm Cavity, 90% Argon Filled Inner Pane: 4mm Toughened Clear, Soft Coat Low-E Glass Overall thickness of 46mm FREE Easy Fit Timber Kerb & Installation Pack Each rooflight purchase includes the following components at no extra cost: Skylight Installation Pack with SOUDAL Low Modulus Sealant (1-3 tubes depending on rooflight size), glazing tape and fixing screws to attach our Easy Fit Kerb to builder's upstand. The 70mm x 70mm Easy Fit Timber Kerb is fixed on top of the builder's upstand and allows to the rooflight to simply slot into place - speeding up installation time and reducing the timbers required on site by 50%. The Easy Fit Timber Kerb drastically reduces faults caused by improper installation and ensures that every rooflight installed is sufficiently supported from the bottom-panes. Self-Cleaning Glass Coating Smartguard self-cleaning coating creates a smooth barrier on the outside pane of glass, helping to prevent build up of pollutants and helps rain droplets wash them away. *Self-clean glass is not a substitute for proper maintenance but is the first barrier between the the glass and pollutants. All building project requirements are unique, it is therefore the client's ultimate responsibility to ensure that the clearly stated specifications of the skylight is suitable for the specific build. The skylight must be installed safely and in accordance with the relevant planning authority, architects, structural requirements, and building and safety regulations.