These adapters are for European speargun muzzles with screw in bands. 14mm-1 specifies a 14mm diameter and 1mm thread pitch. 14mm-1 is the most common threading and is used in the vast majority of speargun muzzles. This correct specification is largely unknown, and pre-made screw-in bands and wishbones are often incorrectly labled as "16mm threading" or "to fit a 16mm head". If you are unsure which adapters fit your muzzle, measure the diamter of the screw opening, it will either be 14mm or 16mm. If it's 14mm these are the adapters that will fit.
Made of anodized aluminum, very light at 0.1 oz (3 g) they will not change the balance of the gun. Save money by making your own bands from bulk rubber, instead of buying expensive pre-made European bands. Available from FreediveStore.com.
