Accuracy
How many seconds a day your watch gains or loses, heard through your phone’s microphone.
Zelos · Hammerhead 1000m Diver Black with Stealth Ceramic Bezel
ChangeHammerhead 1000m Diver Black with Stealth Ceramic Bezel
Somewhere quiet, lay the watch caseback up on something soft. Rest the bottom edge of your phone on the caseback and keep both still.