Adafruit 1871 adafruit 20mm coin cell breakout with on off switch cr2032 adafruit 1871 p the adafruit cr2032 coin cell breakout board is a quick and simple way of adding primary or backup power to your projects it s even sewable for your next wearable project the four output pins are on a 0 1in pitch for breadboarding and provide 2 x gnd 1 x 3v and 1 x switched 3v p p supplied fully assembled and tested but without a battery we stock plenty of suitable a href https www rapido