The APEM Inc. part SMCD131AK2 is a versatile and compact switch thumb-pushwheel thumbwheel that is designed for BCD (Binary Coded Decimal) applications. It has a current rating of 0.1A and can handle voltages of up to 40VAC and 40VDC. This switch is specifically designed for panel mounting on a PC board, making it perfect for a wide range of electronic devices and applications. Its durable construction ensures reliable performance, and its ergonomic design allows for easy and intuitive operation.