... the encoder end. N: The hole dia. Of the user end. * D and L can be defined by user; Standard: ... 30mm. * Diameter of hollow shaft can be defined by user; Standard hole 4mm, 5mm. 6mm, 6.35mm, 8mm, 10mmm 12mm ... please indicate)M: The hole dia. of the encoder end.Φ4,Φ5,Φ6,Φ8,Φ10,Φ12,Φ15mmN: the ... 5M3BF6625345.5M3BF8825345.5M3BF101030426.5M3BF121230426.5M3BF151530426.5M3 Aluminum Encoder coupling 2830-5mm