HI Jacky
I have a KP89D (stainless, decocker) the decocker blocks the firing pin from the hammer while simultaneously blocking the firing pin from movement towards the cartridge, allowing the hammer to drop safley. As far as I know the CZ75 has a safety only. I think you have to go with the CZ85 to get a decocker. This is one reason I went with the P89 I wanted a decocker. The P89 is SA/DA. The first shot is DA when the decocker is used. A DAO version is available.
An excellent gun for the money IMHO.
Hope this helps..check the Ruger web site or PM if you need anymore info.