Flexible Ventilation Design
Independent operation of upper and lower sashes: upper and lower sashes can be slid up and down, respectively, freely adjusting the ratio of opening and closing, realizing precise control of air intake and direction of airflow (e.g., the upper part opens to exhaust hot air, and the lower part introduces cool air).
Energy saving and sealing
Upgraded sealing technology: spring-pressurized or foam-tape sealing reduces air leakage and provides more heat insulation than traditional single-pane windows.
Compatible with double glazing: can be matched with Low-E glass or argon gas-filled glass to enhance energy-saving efficiency (lower U-value).
Durability & Safety
Heavy Duty Counterbalance System: Uses coil springs or block counterbalance hammers for greater durability and less frequent maintenance than rope-and-chain models.
Child safety locks: Optional locks are available to secure the lower fan opening to prevent children from accidentally falling.
Space saving and aesthetics
Does not take up space inside or outside: opens without taking up indoor or outdoor space like casement windows, suitable for confined areas (e.g. near furniture or exterior walls).