The collar is smooth both internally and externally and adheres perfectly to the neck avoiding water flushing. The collar diameter is adjustable with an overlapped tear-off area. A zipper is positioned on the back of the wetsuit and its closure happens from bottom up using a nylon web pull. Underneath the zipper, a neoprene strip prevents water from entering once closed. All seams of this wetsuit were glued and then reinforced by internal blind stitching. This makes the external neoprene totally smooth and free of friction in water.