Radiator Humidifiors

A vase with water in will work the same as the radiator attachments if you feel the air is too dry. I put a coffee jar of water inside the piano to help prevent the wood drying out.

We always used to be able to buy china containers which hooked over the radiator and were kept topped up with water.
We used to put an ice cream container filled with water inside the Piano. When it was moved to dd recently we forgot about it...hoping it had evaporated by then.