5K的全名是:SureFire PKEF(Paul Kim Experimental Flashlight) -B 5K，也就是與8K同樣，只是LED色溫比較溫暖
它的型號對照：
Versions Color configuration
PKEF-A 5K Red / White / Green
PKEF-B 5K Red / White / Blue
PKEF-C 5K Infrared / White / Blue
PKEF-A 8K Red / White / Green
PKEF-B 8K Red / White / Blue
PKEF-C 8K Infrared / White / Blue
PK Experimental (Kroma Turbo) Flashlight
Main White LED - 5W
Lumen output, high beam - Up to 80 lumens
Runtime, high beam - 60min
Overall Length - 155mm(6.1”)
Weight with batteries - 190gr(6.7 oz.)
Bezel Diameter - 50.0mm(2.0”)
Tail Cap Switch - 2 stage + Con. click
Marking on body - Surefire & PK logo
Versions - A, B or C type
16 surrounding LEDs - 5mm in Diameter
當年大約只有不到兩百把。順道一題：L6 Porcupine當年大約有五百把。也就是說比豪豬的數量更少！
目前最大的作用就是給小青石當玩具玩！
