Slotline SSI-691 SKM Series Golf Putter Multi-metal construction, incorporating 304 SS, Tungsten and 6061 aircraft grade Aluminum Tri-milled 6061 Aluminum face insert reduces ball contact surface area providing true loft and flat face, reducing ball skid to keep your putts on line and provides a softer, solid feel at impact Tungsten weighting to bring head to final weight and significantly increases MOI, increasing the sweet spot and improving accuracy Slot and Line alignment system insures proper alignment at address 30g total of Tungsten used in the Heel and Toe