Zildjian 13" Transition Stamp Pair of Vintage Hi Hat Cymbals. They are from the 1940's or 1950's with this stamp. They are very thin with the bottom weighing 595 grams and the top weighing 560 grams. They are excellent with no cracks, dents, chips or key holing. I bought them years ago from the original owner. The bottom 595 gram has a few light scratches (that can only be seen in direct sunlight) from the previous owner cleaning it. They are excellent tight and crisp sounding hi hats that will never be made again. My opinion only.