The triangular shape at the end of each arm of an anchor immediately below the point which, by digging into the ground when any strain or pull comes on it, gives an anchor its holding power.
Marring the deck with the anchor is now less of a concern, because the FastHook container as outside panels have two triangle shaped pockets to house the anchor flukes, Velcro straps to hold the shank in place and two rubber filled sleeve pockets to fit the ends of the anchor stock.