Using the instructions on how to measure watch crystals take the two measurements (or diameter of round crystals) plus considering the thickness or height you can determine the type of crystal quickly. First, is it plastic or glass? Glass feels cold to the touch and does not scratch easily, while plastic has a warmer feel to it and usually has visible scratches. Now is the crystal round or fancy shaped? Follow the questions below to help find a crystal to match your watch.


  • Does your plastic crystal have a tension ring inside? (Round plastic walled crystal with reflective gold or silver ring that sits on the inner diameter of the crystal) Try ET, MT, AT, TT
  • Is your round plastic crystal compression fit? (Fit with tension by bowing the crystal) Try PHD, XHD, HC, PKH
  • Is it a round flat glass crystal? Try RMG, XMG
  • Is it a round domed glass crystal? Try XMD
  • Is it a painted edge crystal? Do you have roman numerals on it? Or a gold or silver reflective edge? Try Fancy Glass Crystals
  • Does your round crystal have some specific characteristics? (magnifier window, fits over bezel) Try PA
  • Is it a Hunting Case or Pocket watch crystal? Try HC, PHC, PKH
  • Does your fancy shaped plastic crystal have side walls? Try GS Cylinders
  • Is it a round flat plastic crystal? Try VT


Other key indicators to help determine the type of crystal:


Round glass crystals might have a gasket on the outside

Plastic round crystal with a side wall might have a metal tension retainer ring