I have the same for Yamaha, didn't pay nearly as much.
The caps have been rolling around in a tool box for years now as I found them very difficult to use.
Mainly the height of the external tank is the issue. Too low and it won't siphon enough fuel. Too high and the siphon will push fuel past the gasket in the cap and cause a leak.
I also found the gasket material to be inferior, apparently not chemical resistant as gasoline caused one to partily melt and glue the cap on to my generator.
If I were inspired, I'd add an impulse pump like the Honda uses. No more need for a siphon, or use for the on board fuel tank.
