Ingenious invention based on Dibnah-pioneered principles, for intravenal pressure control when travelling at very high velocity, or altitudes, i.e. over 35mph, or above 1,000 feet, (e.g the Eiffel Tower). Articulated finger ring with glass rod cylinder and adjustable lower shank. 100% Britannia pewter. Hand made in England. Authentic Alchemy of England brand merchandise.