These filters DO NOT FIT the Skuttle receptacle. They are 4 15/16 inches thick (i measured them) and the Skuttle filters are 4 13/16 inches thick (and fit tight at that thickness). The extra 1/8 of an inch stops them from being able to slide them in without crushing them. DO NOT BUY THESE AS A SKUTTLE REPLACECMENT.
We have an older filter box and the filters are becoming hard to find. The big box stores started selling a model that I had to assemble myself and it was flimsy and a pain. I'm extremely happy with my filterbuy filter, we have noticed an increase in air quality and decrease in dust.
My air handler requires a filter that is 21" x 21", but to find that size I would have to pay extra for a "non-standard" size, IF they were available. The website where I purchased my previous filters considered 21" x 21" filters to be a custom size, and they were going to cost me 50% more than what I paid for the 21" x 20" filters that I ended up buying. Enter Filterbuy to the rescue that has legitimate 21" x 21" filters for no extra cost!I haven't actually used any of these filters yet as I still have two filters left from the previous purchase from a website that will remain unnamed. Although I did open the package just to see how they fit. They fit like an air filter should fit, nice and snug with just enough clearance to be able to grab the corners and remove it.The frame is much stiffer than the filters I am currently using, so they don't have the cross flex or what I'll call droop in them like the current filters do. I was able to slide the Filterbuy filter in the channel without having to reach under and push the back of the filter up so it would install correctly. My physical limitations makes it impossible for me to install the other filters without using something long enough to reach under the air handler and then push up on the filter to get the back of it to slide in the rear channel.