Kerv Ring
Tech specs 
MaterialZirconia Ceramic, Resin
Battery lifeDoesn't need charging
RechargeableDoesn't need charging
Water resistanceWater resistant down to a depth of 50 meters
SensorsNFC
Functions 
Activity trackingNo
NotificationsNo
SOS buttonNo
OtherYou can use Kerv to make payments anywhere in the world that displays the contactless MasterCard payment symbol –think coffee shops, public transport, supermarkets and pub chains.
Links 
View onKerv
Amazon US rating
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