"Half AA" battery, or ideally two (Kendal LA9)

I'm looking for two (working) batteries like the blue one in the picture, please. It's exactly the width of a standard AA clock battery, but only half the length. The one in the pic is depleted, as far as I can tell, but its number is SB-AA02 (3.6V). They seem to come in packs of 10, but are so unusual that I doubt I'd ever need that many! Does anyone have one (or two) spare, please?