The clear heads and stampers are specially designed for all stamping, including double stamping as you can see through them. Mediun/Hard.
These stamper heads are made of a unique water clear silicone, which is sensitive and fragile. It is recomennded to put caps on after use to avoid any damage. Never clean with Acetone as they will blur the head. Always use a lint roller or Moyra 2:1 cleaner for cleaning.