ITEM NAME:Mini Magnetic Reed Swith Module Board for Starters Compatible KY-021 for Arduino Product Description Description: Mini Magnetic Reed Sensor Module Board for Starters Compatible KY-021 for Arduino Specification: Import often open Reed switch. The comparator output, the signal is clean, the waveform, the driving ability exceeds 15Ma. Operating voltage 3.3V-5V. Output form: digital switch output (0 and 1). Fixed bolt hole, easy to install. Small board PCB size: 32*14mm/1.26*0.55'' Wide voltage LM393 comparator. Packing weight: 3g Note: 1. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! 2. Please allow 1-3mm measuring deviation due to manual measurement. Included: 1 x Mini Magnetic Reed Module.Included: 1 x Mini Magnetic Reed Module. Import often open Reed switch. Small board PCB size: 32 14mm/1.26 0.55". Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures.