Die Collars are simple, rugged, dependable external catch fishing tools. Operation Run the Die Collar in the hole to the top of the stuck fish. Apply less than one point of weight and rotate the die collar until the tapered threads have engaged the fish. Stop rotation and pull the fish from the hole. Die Collars are furnished in two types: Type ��A�� and Type ��B.�� Type ��A�� Die Collars have a smooth end on the large diameter end, the guide is integral with the die collar.