MULTIPLE SPECIFICATIONS AVAILABLE: 80-135cm retractable optional, you can measure the distance according to your window and choose the specifications that suit you, with power supply, suitable for home and commercial use RETRACTABLE: 5CM retractable, no need to worry about not being able to install, three-stage caliper structure, firmly clamp the edge of the window frame, with thickened spring, prevent falling, safer and more reliable PUNCH-FREE UNIVERSAL TYPE: "Click" to complete the installation, no need for punching and tools, does not affect the opening and closing of windows, installed on the edge of the window frame, free installation and use, no need for decorators, easy to add tables without modification EASY TO INSTALL: It can be firmly clamped on the edge of the window frame, and the installation is stable, Prevent falling, easy loading and unloading, can be directly flushed and dusted, unlimited installation position, no need to open holes, can be installed on the left or right side, can be installed anywhere Widely used: quickly exhaust odor and heat, drive away smoke, odor, hot pot smell, reject humidity and heat for healthier, suitable for chess and card games to remove smoke, vertical installation of sliding windows, deodorization and ventilation for pets, horizontal installation of casement windows