2 engine order telegraph discs from a ship, possibly Navy. The black is transparent, light shines thru the words, it's made of bakelite or plastic. The white one is not transparent and is made of aluminum. Each has 3 mounting holes. Both measure 6 1/2" in diameter. Center hole on the black one is 1 1/8", the white one is 1". Both are about 1/16" thick.Payment by PAYPAL only and shipping within the USA only. Thanks Take a minute to browse my other nautical items and photos.