I bought some of these here, same thing
https://www.taydaelectronics.com/datasheets/files/A-3003.PDF
https://www.murata.com/en-us/api/pdfdownloadapi?cate=&partno=PKM13EPYH4000-A0
and there's no clear polarity marking on them, and I don't see any mention on the datasheets either, or am i missing it ? I see 30Vpp
On the top, over a pin, the M for Murata is inside a square, might that be the Negative ?
https://www.taydaelectronics.com/datasheets/files/A-3003.PDF
https://www.murata.com/en-us/api/pdfdownloadapi?cate=&partno=PKM13EPYH4000-A0
and there's no clear polarity marking on them, and I don't see any mention on the datasheets either, or am i missing it ? I see 30Vpp
On the top, over a pin, the M for Murata is inside a square, might that be the Negative ?