Synthesizer Design Letter Set Greeting Card Synthesizer GC-39. I imagined an analog synthezer. For product name and segment LCD number It is also "39" with the meaning of thank you. It is perfect for gifts and message cards. A special silver paper that is slightly thicker is used. You can write a message on the back. The envelope is a matte black cotton envelope. It reproduces the atmosphere of a synth hard case and creates a synthesizer feel. Also, the card is postcard-sized. It can be used not only as a stationery but also as a postcard. <GC-39 Silver Product Details> 1 envelope (2-inch envelope) 2 cards (postcard size)