The size or gauge of the zipper refers to the width of the teeth of the zipper. A #3 coil zipper would measure approx 3mm across the width of the teeth, while a #5 zipper would measure approx 5mm.
Our standard coil zipper for the Darien and DangerBird is the #5 coil zipper. The heavier #5 zipper is generally more durable and less prone to damage than the #3 if the user is a bit rougher with their gear.
An 11ft length of #3 zipper and a pair of #3 zipper sliders weigh 1.4oz (39g).
An 11ft length of #5 zipper and a pair of #5 zipper sliders weigh 2.75oz (78g).
The difference in weight would be 1.35oz (38g)
The Sparrow & Raven hammocks use a #5 separating zipper.
The Darien & DangerBird use your choice of a #3 or #5 non-separating zipper.