This range includes the sub-miniature crystals produced by River Electronics, manufacturer of the smallest micro crystals in the world, along with the ubiquitous 32.768kHz crystal, which they reduced to the footprint of 1.6×1.0mm with a height of just 0.5mm.
This latest product has been developed also for the use in smart card applications where the crystal is embedded within the thickness of the card as part of the control and security circuit.