InvictaMen's Pro Diver Automatic Watch, 30091, 40, 42, Diver

what is the difference between the Invicta 29178 and the 30091, they look the same?

Invicta 30091 what movement does it use?

Does this watch have a battery?

How difficult is it to take out links to size the band? The couple of jewlers I taked to, said there a pain to size. Do they have the basic push pins?