"I asked for a custom size (86") and they were happy to accommodate. The shelf is high quality wood and looks great, and since there are no visible brackets and it is the perfect length, it looks like it was part of the original plan for the house.
I have it in my (very small) kitchen above the cupboards, and so I also requested that it have a small lip to prevent things from falling, and the seller agreed to do that as well. It has added a ton of essential space, and despite being a pretty pricey shelf, I'm so glad I bought it!
As far as installation -- I am by no means a handy person, but I have some tools and was able to get the floating bracket mounted by myself. It was a bit of a struggle and took a few hours, but it turned out well and was proud of the job I did. I did need another person to slide the shelf on."
Alder Solid Hardwood SMOOTH Floating Shelf