This Horotec snap on watch case back closer dies come in a set of 8 reversible thread on dies plus 1 universal die.
The watch case closer die sizes are:
17mm, 19/21mm, 22/25mm, 26/29mm, 30/33mm, 34/37mm, 38/41mm and 42/45mm plus a 45mm universal die.
The Horotec dies are delrin a thermoplastic used in precision parts that require high stiffness, low friction and resists changing shape. Delrin is said to be the bridge between metals and plastic.
Use with Horotec Deluxe Case Press or Horotec Standard Case Press.