The VCM opening skylight for flat roofs is the cost effective solution for natural ventilation. The pre-installed Insect Screen adds the benefit of keeping mosquitoes and flies out in summer
Product Features: 
Maintenance free – White PVC interior frame for a tough interior finish
High Performance double glazing as standard, with NEAT™outer coating: reduces cleaning frequency
Includes removable insect screen
Outer aluminium cappings (grey)
Available in 6 sizes
Operated by winder handle for within-reach situations or by rod for out-of-reach use. (sold separately)
Requires custom-made flashing (not supplied by VELUX)
Approx 75% heat block