This is a Disc Golf putting grip where you rest your index on the rim to stabalize the grip when your throw has slowed down. It does help slow down your putt but the grip would vary from your drive grip which some say is a bad idea.
Disc Golf Turbo putting - this is a unique style of putting. You start with the disc parallel with your ear. Your thumb should be on the center part of the disc. You fingers should be on the outside of the rim opposite your target. You rotate your fingers from the back of the disc to the front while pushing the disc forward all in one motion. You would throw the disc like you would toss a pizza but instead of throwing it up you throw it forward. The trick to this is it's all in the spin. Very little push forward vs spin.