That would be an "Unequally Disposed Profile Symbol" which becomes a unilateral profile, since it's a tolerance that only adds material from the nominal. It creates a tolerance zone of .008 units in size, starting at the nominal and extending .008 units away from the nominal surface in the "adding material" direction.
I do not believe there should be a vertical line preceding the second .008 - that's all part of the same 'box' / 'definition' with the (U) symbol.
That is, of course, coming from 2009 of Y14.5 since it's the one I'm most familiar with. Others may vary.
For the 3 year old:
That's a camel's back symbol! The camel's back means the part gets a BIG HUMP on it that's EIGHT BIG!. It can't get smaller because the camel will get sick

but the camel can get a hump that's 8 big! Bigger than 8 and he might POP! And that'd be bad. We don't want the camel to get sick OR to pop ! We like the camel when his hump is flat or up to 8 big.
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NX8.0, Solidworks 2014, AutoCAD, Enovia V5