VeLux Skylights, Roto Frank of America, Marvel, Rain Sensors, Sentry II Automatic Roof Window Operators, Velux Skylight Systems, Sentry II WLS systems, Sentry II Remote Skylight Parts, Truth Hardware for Skylights, push-out hardware, wands, crank extensions, manual style roof window operators, hinged skylight hardweare Motorized Hardware, Surface Mount Seals, Kerf Mount Seals, T-Slot Mount Seals and Pocket Mount Seals for skylights Marvel Operators, Galaxy and Stella by ROTO Frank, discontinued parts (1) If you can’t find the seriel number and model – Measure the width and length of your skylight. Provide the width dimension first, then the length. Measure anywhere inside or out. (2) Take some good, clear digital pictures. Both inside and out, operable gears with chain, spring loaded arms on side, hand cranks etc. – Email To: Info@WeFixItUSA.com