Provides a variety of useful inputs and outputs for various projects.

Three linear slide potentiometers connected to Arduino analog pins A0, A1, and A2.
Red and yellow LEDs connected to digital pins 5 and 6 (PWM pins) so you can easily vary their brightness.
Three momentary push buttons connected up to the Arduino’s digital pins D10, D11, and D12. Those lines will go low when the buttons are pressed.
A photocell and a temperature sensor, both with analog outputs, are connected to the analog pins A3 and A4, respectively.
An 8-bit shift register set up to control a blue 7-segment LED.
Two buzzers. One is used as a speaker, the other is connected to analog pin A5 and can be used as a knock sensor.

IMPORTANT: There is another Danger Shield manufactured by Seeedstudio. Both designs refer to the idea of Zach Hoeken / NYCresistor. But have slightly different features (Slider LEDs, sensor types). Please compare schematics if you care about the differences.

Arduino Sparkfun Danger Shield Pinouts