I had been looking for exhaust for washrooms and these designs with collapsible flaps looked great considering that it prevents insects and mosquitoes entering via washroom. Having good history with this brands product, I went ahead with the exhaust and with a few minor things it turned out a good decision. One year plus and its still running fine.•••••••••••••••••••🎁 INSIDE BOX•••••••••••••••••••1x exhaust unit1x operating manual4x screws4x nylon sleeve2x rachet screws with square nuts (can be used as an alternative fixing arrangement, either on frame (details below) or to hang it from the top side)Cable length: 55 cm➕ PROS1. Its made of plastic, but have a solid built and motor also looks sturdy.2. Capacitor arrangement is hidden inside a pocket on one of the corners3. Length of attached cable is more than sufficient to reach power point even if above the false ceiling4. Suction is good and 200mm model air flow is sufficient for washroom use case (I have installed these in 8'x5', 9'x6' washrooms)5. Flaps are quite useful, as they prevent insects and mosquitoes when exhaust is not in use6. Noise during operation is on the acceptable side and you wont notice it from other rooms if left on. Its kind of noiseless, if if has unobstructed incoming air flow from some areas in the house.7. Two way fixing arrangement - One may fix it via 4 screws by drilling 4 holes on wall/aluminium frame, or use rachet type screws to avoid drilling holes if the existing arrangement supports the way (possible with modern aluminium window frames with square portion with removable glass reserved for exhaust). I fixed it via rachet screws.➖ CONS1. Flap arrangement is a hit miss kind of, and may be your unit is not that smooth. In one of my exhaust, it is like stuck and opens half way only, unless forced. I tried a replacement but it had the same issue.I had to remove the flap assembly and clear the plastic component (small plastic shaft kind of) which attaches to main body to make flap swivels around.2. Oil collector tray is kind of useless, since there is no ditch around circumferential edge which can collect all of the oil and drip in the tray. Its a design flaw, which may render tray useless.⚙️ ASSEMBLY & INSTALLATION- DIY1. It comes in assembled state but in order to fix it you may need to partially disassemble it2. Design is modular, to most of the pieces are press fit3. Rotate spinner to remove it and subsequently remove the blade4. Remove front panel to reveal holes for screws5. Clear the area of glass and frame, if its there in the exhaust's place6. As your case is, either drill holes on wall/frame marking positions (hole dia will vary accordingly- sleeve thickness for wall and screw thickness for frame) and fix via 4 screws with or w/o nylon sleeves (if fixing to wall nylon sleeve required, and if directly to aluminium frame, screw can be directly used)6. Or use rachet screw on two holes at the center of two sides while attach square nut and if required a bigger washer. Tuck nut and washer to the back side of aluminium frame. Holding it via something, tighten the screw via racket head until it fixes.P.S. Don't tighten any of the plastic nut, spinner, or ring screw beyond a point; otherwise, it may slip. You need to find the threshold intuitively.Also, follow dimension guide in the product images carefully to select the model-150mm version if your space is > 170x170mm and < than 240x240mm200mm version if your space is > 170x170mm and < 290x290mm250mm version if your space is > 290x290mm🏆 VERDICTThis exhaust works great if it has unobstructed incoming air. Remember what goes in comes out, so in order to exhaust volume of air, it will need that volume of incoming air, so somewhere across the home some window or duct must be open to provide that volume. Else it will make noise, since it has to work hard to pull in air from edges of doors and windows.