I got these: https://www.pearl.de/a-ZX7311-3110.shtml;jsessionid=nAF84CDBD95715305C44924424332C488?vid=953&curr=DEM
Not sure how precise they really are but they connected easily. Have them running for 34 months now, they run for months on rechargable AAA (I got high quality ones, Varta I think)