FluvalU2 Underwater Aquarium Filter 110 Litre (30 US Gal), with EU Plug

Does the whole unit go under water? No spray bar to make a noise? All the aeration underwater bubbles? My filter at the moment very noisy!

Hi does the filer come ready to use or do I have to buy the filters and foam seperately?

I have lost the grey stopper that regulate the slow from the top filter. Is it possible to purchase these separately please?

Will this filter work if I use it horizontally on its side, rather than vertically? I want to use it in my turtle tank which has a low water level