You will receive an engraved selenite charging plate similar to the ones in the photo. These are made to order. They have the moon phases engraved on one side. Size is approximately 7 3/4" x 1" and about 1/4" thick. They may be larger but will not be smaller than that.
Selenite crystals work to help you to bring light down from the higher realms into the physical body, to create personal transformation.
The white or transparent crystals have a strong vibration that may open the crown chakra and the soul star chakra.