we use this zip boot for more watersports than we can mention , the 5mm neoprene is ideal for uk climate and zip for ease of putting on. There is a panel behind the zip which is better for drysuit use. We always suggest going up a size as we know they come up small so if size 8 order 9. For drysuits with feet we suggest go up 2 sizes. if unsure message or phone me.