Thank you for looking. This is a white-logo (60s-70s) A Zildjian Medium Ride cymbal. No explanation is needed for this one; it's a classic, a cymbal that created a world standard. It might be perfect as an introduction to vintage cymbals. Judging from the logo, it appears to be from the 1960s. Although I couldn't observe it with the camera, there is the word "Ride" under the stamp, and a stamp that says "Medium" diagonally in the upper left.