This is a very rare Karsten Co. Anser Jack Nicklaus/Slazenger putter. This putter was made in 1968 but is unknown to many collectors, as only about 300 of them were ever made. Slazenger had the Distribution rights in Canada and Europe for PING. Slazenger also had a side deal worked out with Nicklaus so that's the reason why both names ended up on the putter. A majority of these 300 putters were sent to Europe, which explains their rarity in the United States today.