The batteries in the (440 Pro) remote are 3 x AAA. The ones mine came with are pale grey and silver, with silver lettering. There is no brand as such, unless it's "ALKALINE" which is in large, friendly letters (seems a bit unlikely). Perhaps predictably, the text "made in China" appears in much smaller letters. It looks to me as though they might be old stock, given they are marked with what's presumably an expiry date of 10-2017.
Roon (Mac Mini), Wilson Benesch Full Circle, Expert 1000 Pro CI, Kaiser Chiara
Warwickshire, UK
