5pcs DC 3.3-5V 0.1mA UV Test Sensor Switch Module Ultraviolet Ray Sensor Module 200-370nm for Arduino
Analog UV Light Sensor Breakout - GUVA-S12SD : ID 1918 : $6.50 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: UV Sensor (C) Compatible with Arduino/Raspberry Pi, I2C Digital Ultraviolet Sensor Module with LTR390-UV-01, Embedded ADC, Direct Light Intensity Value Output via I2C Bus, Less Noise Interference : Electronics