This membrane keypad has a single key, but it does have an embedded surface-mount red LED installed. The flex cable is also extra-long, so they can think of a lot of theyarable and portable projects that would use this sort of switch and have an LED as feedback (say, to indicate that an action is occuring or the power is on). Since the keypad is soft plastic, it can be sewn with needle and thread.
The back of the pad has a removable paper cover that protects an adhesive backing. You can see how the pins correspond to the LED anode/cathode and button by looking at the photos above.
Adafruit include a 3-pin extra-long header strip so you can plug this into a breadboard with ease.
Membrane LED Keypad + extras (14:05)
- Weight: 1.97g
- Keypad dimensions: 19.05mm / .75" x 34.92mm / 1.37"
- Length of cable + connector: 350mm / 13.77" x 8.24mm / 0.32"
- 5-pin 0.1" pitch connector