Respond to these showcases www. ajplus. co. uk/ajdirect Readers may obtain information about these products by filling in the enquiry numbers on an AJ enquiry card. Advertisers wishing to promote their products on these pages should Not only are they the safest rooflights for non-fragility but independent research has shown that CA's systems have the best insulation. Hot-box equipment demonstrated a U value as low as 1W/m 2K, saving on energy for heating as well as lighting.