Strobist
Rosco, the worldwide leader in color filters has assembled the essential collection of filters for use with your on-board flash. Rosco has been manufacturing color filters since 1910 and our Cinegel range of color filters has earned two Academy Awards™. The Strobist Collection contains the Cinegel filters photographers need, properly sized (1.5" x 3.25") to fit most shoe-mount strobes. There are 20 different colors inside with multiple pieces of each color for a total of 55 pieces of filter.
We represent ade sell Strobist in the Czech Republic.
Strobist contents : 
Cinegel #3202 Full CTB - Cooling Filter
Cinegel #3204 1/2 CTB - Cooling Filter
Cinegel #3208 1/4 CTB - Cooling Filter
Cinegel #3401 Sun 85 CTO - Warming Filter (Converts 5500° Flash to 3200° Tungsten)
Cinegel #3408 Sun 1/2 CTO - Warming Filter
Cinegel #3409 Sun 1/4 CTO - Warming Filter
Roscolux #08 Pale Gold - Warming Filter (With a small amount of pink for skin tones)
Cinegel #3304 Tough Plusgreen - Adds green to flash to match cool white fluorescent bulbs
Cinegel #3415 N.15 Neutral Density
Cinegel #3403 N.6 Neutral Density
Cinegel #3404 N.9 Neutral Density
Roscolux #12 Straw (Yellow)
Roscolux #23 Orange
Roscolux #26 Light Red
Roscolux #33 No Color Pink
Roscolux #39 Skelton Exotic Sangria (Magenta)
Roscolux #358 Rose Indigo (Purple)
Roscolux #80 Primary Blue
Roscolux #375 Cerulean Blue (Cyan)
Roscolux #90 Dark Yellow Green