The old Salvimar shafts were no good because the wire tabs would not hold the wishbones, the bands would slip off the rounded wire tabs.
Old Salvimar shaft with poorly designed wire tabs
In contrast the new (2020) Salvimar Pacific shafts, available from www.Spearfishing.store, are very nice. The sharkfin tabs are strong, hold the wishbone well, have a spacious hole in each tab including the rest tab, and are aesthetically pleasing. They are hard (17-4PH stainless steel) and bend resistant. The flopper is heavy duty 3" long, positioned on the bottom of the shaft. I prefer the flopper on the bottom, if on the top it pops up when aiming the speargun at a downward angle blocking the fish/target from view.