100% open area,Double side sealing and Multi-point locking,Option of mosquito mesh possible,Prevents Dust and Air-leakage,Good Sound Insulation,Can lock at ventilation position,Outside Clearance area required equivalent to sash width,Poor sound insulation.

100% open area,Double side sealing and Multi-point locking,Option of mosquito mesh possible,Prevents Dust and Air-leakage,Good Sound Insulation,Can lock at ventilation position,Outside Clearance area required equivalent to sash width,Poor sound insulation.