MetalSandTimerSuppliers . Measures 3/ 5/7 minutes . Great for brewing black, green or herbal teas . stainless steel frame . Size : 9 x 8 x 3 cm . Sand color : black / green / red / custom This is a kind of 3 in 1 metal sand timer. As its name, the frame is made of metal. And 3 glass bulbs in one metal frame. Generally the time of each bulb is different. The normal one is 3, 5, 7 minutes. But you also can make them same if you like. Company IntroductionMetalSandTimerSuppliers website:http://www.skyringe-crafts.com/sand-timer-hourglass/metal-sand-timer/