I had one of the type through covers from the keyboard company to use with a desk top pc I used and it was useful because it could protect the keyboard from spills and dirt.
The idea of this it to put it over the keyboard and then still be able to type and use it like normal but protect it from harm at the same time. I did think it was a bit odd to use first few times I used it and it felt strange typing on a cover over the keyboard.
If you give it time it will grow on you and if you are working in a situation where maybe you have dirty greasy hands from working or have been in contact with things that would be bad for a computer keyboard this will be a good idea to have. It can help to protect the keys and the main body of the keyboard all in one.
Polyurethane is what is used to make the cover and there is no latex or rubber to cause a reaction for people with allergies to that. I didn't find the product irritated my hands when I was using it.
The cover will fit a good sized keyboard and the size is roughly 48 cms wide and 16 cms deep. Its very light and easy to use and when you get used to it you can still type and use your keyboard with no worries. You wont get dust or dirt on the keyboard and you can wipe the cover if it needs a clean.
I think that this can be very useful for work situations when you are working in manual jobs mostly but need to use the computer sometimes. It could be handy for anyone who likes to keep their keyboard clean and dust and water free.
The only problem with this is that it won't fit curved shaped keyboards and I don't know if you can get a shaped one for them or not. The cover is not cheap and can be about £20 to buy, but when you think it can help to protect what could be an expensive thing to replace it is a good idea.