The Sinus Zero Line was the first putt and approach golf disc released by the Swedish company Latitude 64. The Sinus has a very flat top with textured grip pads for your thumb. The Sinus is slightly over-stable, allowing it to be thrown hard on longer putts/approach shots without losing consistency. This Hard edition really lets you feel the disc's shape and adds grip in warmer climates. Zero Line plastic is awesome with a sticky, but not tacky feel to it - Great for leaving your hand and sticking to the chains. Zero is now made in Soft and Hard types to suit the player's preferences and climate!