PWM Y Splitter Cable with Black Sleeving (Correctly made version with only 1 tachometer wire) Y Splitter for 4-Pin PWM Fans Tachometer wire on just one lead (motherboards/fan controllers can't correctly read a speed signal combined from 2 fans) Black mesh sleeving This cable does not require modding for accurate speed readings due to only having only one tachometer wire going to one lead