Auto fill cells depending on another cells content

I'm OK with Excell, but by no means an expert.

I'm creating a sheet that will calculate gas purge volumes, and I've got most of the cells sorted with calculations based on other cells, but one of them is giving me a headache. It's probably simple for those with experience. So...

I have cell E2 which contains a drop down list (linked to another sheet) which gives options (which are meter sizes) E6, U6, G4, U16, etc. What I'm trying to do is get the column F2 to auto fill depending what is selected in E2. So, if someone selects meter size U6, cell F2 will auto populate with the number 0.0028, if they select meter size E6 then cell F2 will auto populate with the number 0.008, etc

Sorry if the use of E6, U6 etc complicates things, those are the actual names of the meters.

Any help is greatly appreciated.