Power Rib Shooter's Paks - Shooter's paks for Smith & Wesson K, L and N frame revolvers contain a Power Rib mainspring and 1 each of 13, 14 and 15 pound reduced power rebound springs allowing optimum adjustment of the hammer and trigger functions. As mentioned above, these paks can often take the place of expensive "trigger jobs" with better results.
Type 1 Pak - Includes a Ribbed Factory Power Standard mainspring.
Type 2 Pak - Includes a Ribbed Reduced Power mainspring.
Wolff is top shelf
I have trusted Wolff springs for 40 years, and bottom line is they have NEVER let me down.