They're not magic... just good 20 and 30 yard chokes. They measure about like skeet and light modified, and I could never figure out what 'WS2' had to do with the game of skeet. I use spreaders in my WS2 choke when shooting skeet.

A Beretta mobilchoke or optima marked 'skeet' has a similar interior profile to a WS1, and performs the same.

"The price of good shotgunnery is constant practice" - Fred Kimble