A customization kit, conceived for the K10 and inspired by the New version of the K12 air pistol, was introduced last July. It allows the upgrading of all the K10s so far marketed. The kit includes an ergal barrel-cover which can be screwed up to 8 counterweights of 5 grams each. The barrel-cover, 45 grams, can be easily inserted on the barrel after removing the front sight ramp and secured by tightening two Allen screws. The operation is very simple and can be done by the shooter. Manufactured in 4 different colors (black, silver, red and blue), the new barrel-covers match the 6 air cylinders already available (black, silver, red, blue, white and pink) to provide a total of 24 color variations.