[SDKJapan]

Rob,

I think Josh has already responded, but I will add what I found to be sure.
As he noted, you can purchase distilled water branded specifically for CPAP use, but its expensive on Amazon and other online sites in Japan. I think your client could refer to the Amazon link and decide.

https://www.amazon.co.jp/%E3%82%B5%E3%83%B3%E3%82%A8%E3%82%A4%E5%8C%96%E5%AD%A6-CPAP%E7%94%A8-2L%C3%979%E6%9C%AC-%E3%82%B7%E3%83%BC%E3%83%91%E3%83%83%E3%83%97-%E9%AB%98%E7%B4%94%E5%BA%A6%E7%B4%94%E6%B0%B4/dp/B09DCGZ7HP?th=1

Scott

FYI–=CPAP machine maket Information page:

https://www.cpap-japan.com/pages/using-cpap-in-japan