Item no:AT-MA 

最傳統及最經濟之開窗系統
可操控多至十個窗戶
可開啟窗戶達400mm

Traditional and Economical Opearte to 10 sashes at once.
Window opening as wide as 400mm

AT-MT
手動臂開窗系統
Manual Torque Arm opening system

AT-MB
手動開窗器
Manual Chain Box