4' x 25' Flashgro Mylar on White Hydroponics Reflective Film Metalized polyester surface with a tough woven poly backing material Flashgro reflects both heat and light in an even dispersed pattern Great for use anywhere in the grow room as it can be stapled, nailed, or glued to any surface. This film's high durability makes it reusable and easy to clean Measure at 4 feet x 25 feet