I've done plenty of the Mark series sondes and batteries from Olga. You will see a slight difference in power (depth) as a red sonde from Olga I expect to work like a yellow sonde from Vermeer. Vermeer doesn't manufactor the Mark series anymore so that's why I have done quite a few from them. No worries,
This is CABL.com posting #376827. Tiny Link: cabl.co/mbKb1