Ihab, the most important consideration is the size of the shaft notches. If you have a Riffe-style shark fin shaft, then you can use thick wishbones - I make my own from 1100# Spectra. Those will outlast your band 10 times over. If you are using the Rob Allen-style notched shafts, you should probably stick with with something 2mm or less. 1.75mm is probably best. These won't last as long, but you can tie your bands to allow you to change the wishbone if it gets frayed - check out
Home of HammerHead Spearguns to see the style of wishbone I'm talking about.
