K&H Pet Products Kitty Sill Perch

It's a nice, roomy size, soft, and attractive. I've had it a year and a half. Both cats love to sit on it to birdwatch, or to take a nap. The cover is nice quality, stays on well, and is easily removable for washing. Love the heating pad, it functions just right. I leave it plugged in 24/7 year round, as we tend to keep the heat low in the winter and the AC high in the summer. There are a few things that could be better. The whole frame under the cushion is a cheap plastic grid. It's starting to sag on one side. Worse is the velcro tape for attachment. It held for about a week, then detached and dumped the cat on the floor when he jumped up onto it. I bought some more heavy duty velcro adhesive tape and added it, but there's just too much of the seat extending from the windowsill with no support. I have about a 3" windowsill depth... maybe it will work fine for you if your windowsills are considerably deeper than that. For now, we've added a jack stand to it, which doesn't look great, but keeps it in place even with both cats (25 lbs total) are sitting on it.