LIMTED EDITION CASE COLORS! FOR A SHORT TIME WE HAVE 6 COLORS OF THE CASE BESIDES BLACK. CLICK ON YOUR CHOICE! Unique, patented arrow and circle design creates a visual anchor that promotes a repeatable stroke and real time confirmation of a correct backstroke path. The pocket sized Putter Key helps you center the ball and transform your putting performance by matching feel with real time feedback to groove your stroke. Included: Outer box, jig applicator, carrying pouch, extra adhesive, alcohol wipe, and expanded instructions. PRODUCT SPECIFICATION The Key Dimensions: Length: 2.5 inches Width: 1.2 inches Height: 0.08 inches Weight: Ultra-lightweight: 0.3 ounces (won't affect putter balance or feel) Materials: High-grade carbon fiber construction Medical-grade proprietary adhesive system UV-resistant coating for durability Compatibility: Fits 95% of putter designs including: Blade putters (all sizes) Mallet putters (standard and oversized) Does not fit on all center shafted putters Works with both right and left-handed putters Temperature Range: Optimal performance: 32°F to 120°F Adhesive maintains bond in all weather conditions