Surfing Waves

Im looking to buy my first wetsuit and there is a good sale on the xcel axis suits at a store near me but there are different ones available, the x and os I believe. I did some googlin trying to find the differences but couldn't find anything. I live in Seattle and will mainly be surfing water 50-60 f and haven't yet decided on a 4/3 or 5/4.
Thanks

X is front zip and OS is back zip. Otherwise I think they are exactly the same.

Which is better front or back? Its an entirely personal thing. Front is generally more flexible but harder to get in and out. Back slightly less flexible (because the zip isnt flexible) but much easier entry.

for 50F I would go for a 5/4 (and a hood and preferably with a move to somewhere warmer). However, if you get a 4/3 you can add a 1mm/therma rash vest underneath for the colder days and it might be effective.

everything that dtc said above + front zip is a little bit warmer than conventional back zip. Caveat is some back zips have bat wings, drains and other features that prevent cold water from running down your back.

Wound up getting the infinity tdc 4/3 front zip hopefully I won’t regret it come winter. Is the tdc actually anything or just marketing?