Easy to use:4 positions(0-1-2-3):Position 1:(B - C)/(B - L)/(B - M)/(B - H)OFF;Position 2:(B - C - L)ON,(B - M)/(B - H) OFF;Position 3:(B -C - M)ON,(B - L)/(B - H)OFF;Position 4: (B - C - H)ON,(B - L )/(B - M)OFF.
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