The Ultimate line of CZ parts and Accessories were developed by 7 time IPSC World Champion Eric Grauffel to support the CZ 75 line of sporting firearms.
The Ultimate recoil spring is compatible with all CZ 75 type models, like the shadow, shadow 2, TS, Czechmate...
They are available in 8lb, 9lb, 10lb and 11lb weights.
11lb is recommended for Production Optics to increase the life of your slide mounted optic, as well for .40S&W and 9mm major models.
10lb is good for general use in 9mm.
8lb and 9lb springs should be used with a shock buffer .
Please remember that recoil springs wear and must be repolaced every 5000-7000k rounds.