Specifications：

1. Economic and reasonable structure, good water and air penetration.
2.Surface treatment: PVC.
3.Hardware: ROTO, SIEGENIA, China hardware etc, others (Europe standard channel)
4. Sealant: EPDM, PVC, SILICONE ETC.
5. Glass: Single or double glass (tempered glass, figure glass, frosted glass ,coated glass, low-e glass, tinted glass etc.