Hi Jryffel
Vitler make a single/mono screw
Nothing wrong with a mono screw, just they haven't kept up with the times on my side of the pond.
Priced a maintenance contract with a HS35 on it recently, looks like I am going to see quite a bit of mono screws in the next few months
Have you a link to the Vitler site so we can have a look see.
Regards. Andy