This a view showing the projections inside the center hole of a Hickock side tab LRI. The embossing is up on the side of the top rim. The patent is referenced here: http://reference.insulators.info/patents/detail/?patenhttp://reference.insulators.info/patents/detail/?patent=U-23373t=U-23373 The glass is a typical deep aqua, bordering on teal. This one has interesting spider cracks throughout.