Replacement Electrode HolderReplacement Electrode for Manual Manipulator Left Hand M3301L and Right Hand M3301R Comes in Black only 14 cm long x 7. 2 mm diameter M3301EH comes in two colors. The clear M3301EH (shown below) comes with the purchase of a micromanipulator like the M3301L or M3301R. If the M3301EH is ordered as a replacement part, the black version of the electrode holder is shipped. Both handles function the same, but the color is different.