Jim
Whilst we don't know the exact salt level in this cure, we do know that at 15g per kg, it can't be above 1.5%.
Given even the old EU curing rules (they changed recently) set at 300 mg/kg Nitrate and 150mg/kg nitrite maximum, and that the main website says "...This ready mixed formula is a mix of salt sodium nitrate and sodium nitrite...", the best estimate of the level of salt that this cure alone will give is 1.46%-1.48%.
We await the reply to Dave for clarification. Some cure manufacturers are loath to give details of the contents of their cures for commercial reasons - personally, I won't use a cure if I don't know what's in it.
Like Dave, my family like a fairly low-salt product, at least this cure gives that, and you can always add more salt. My problem in the past, with others, has been the opposite and salt's a lot harder to take out than put in!
Phil