Does the job, but could be better...
Very fiddly to fit, and it isn't made clear that it is shaped to fit round three sides of the window only. Therefore for UPVC windows with hinges where the whole window pivots away from the frame, you will have to adapt it to fit on four sides. Additional double-sided tape/Velcro to ensure a seal where the ends meet is not provided. The stitching attaching the Velcro tape to the fabric is not as strong as the tape itself, so it tends to rip off when you separate the tape. For the price of the item, I would have expected something more robust.
Still... once you have it installed, with modifications, it will provide a seal as stated in the description.
Verified purchase: YesCondition: New