OULAI window handles are used for popular casement and top hung upvc window. The materials are aluminum ally, zinc alloy. Variety colors for you to choose, white, gold or customized ( RAL Color Standard ). The Production Processes are 1.Mould, 2.Forging, 3. Die-casting, 4. Acid washing, 5.Processing, 6. Polishing, 7.Lacquer / powder / coating / painting / anodizing. Welcome to consult.