Quantity   Component name
1 × Arduino Generic Arduino Nano
1 × Audio Amplifier SparkFun Mono Audio Amp Breakout - TPA2005D1 https://www.sparkfun.com/tutorials/392
1 × Battery Charger SparkFun LiPo Charger Basic - Micro-USB
1 × Battery Lithium Ion Battery - 400mAh
1 × 3 V to 5V Battery Booster https://www.adafruit.com/product/4654 (3v to 5v)
1 × 7 Segment LED Display With controlling circuit. https://www.adafruit.com/product/878
1 × Momentary Switch
1 × On/Off switch
1 × 8-ohm speaker
1 × Ultrasonic Sensor HC-SR04 https://www.sparkfun.com/products/15569