Abstract: A single Airbed style earphone employing a standard three-conductor stereo headphone plug is adapted to enable the use of one earpiece to hear the combined left and right channels of stereo audio in a single ear. The single Airbed invention employs a three-conductor plug and is wired in such a way that it may be used equally well with both stereo and mono audio devices without the need for any kind of adapter, switch or sensing circuit. A pair of resistors matches the impedance load of a stereo headphone set.

Abstract: The prism glasses include movable prism lenses and, optionally. detachable temples. The movable lenses permit the user to alter the viewing angle from substantially 90 degrees downward to substantially 90 degrees upward. The glasses include a planar frame plate, a bridge, a forward outboard face and view ports therethrough. Two prisms, one for each view port, transmit the image. Prism frames have mounting elements for attachment and detachment to complementary mount elements on the frame. The mounts permit either rotation or removal and re-insertion on the frame. In a first mode of operation, the prism transmits a 90 degrees image. The prism mounts cooperate with the complementary frame mounts and the prism lenses can be (a) removed and re-positioned at a 180 degrees position or (b) moved 180 degrees from the downward 90 degree viewpoint to an upward 90 degree viewpoint to the second operational mode.