Dial in your putter to fit your eye with the M Craft X Four back piece - a squareback type design with a single alignment line behind the ball, as well as two alignment aids running parallel to the face. Our patented design uses the weights to hold the putter together, allowing you to change weights and back pieces to customize your putter to your preferred weight and look. *Must have M Craft X Tool and Club Wrench to properly disassemble and reassemble putter. Not included.