Button Cell Battery, 27mAh, Silver Oxide
From Amazon
VARTA Watch V377 - Silver oxide battery (SR66, 1.55 V)
Conrad Electronic
Varta Button cell SR66, SR626 1.55 V 1 pc(s) 21 mAh Silver oxide SILVER Coin V377/SR66 Bli 1
BatteryUpgrade
Varta V377 (SR66 ) Coin cell battery (Amount 1)