Thermometer and Hygrometer, Stainless

Two dials, one gauge, no batteries.

The upper needle reads the room temperature, from 70 up to 250 °F, with the band a sauna usually runs in marked in orange so you can see at a glance whether you are in it. The lower needle reads relative humidity from 0 to 100 percent, which is the number that tells you whether the heat will feel dry and sharp or heavy and close.

The case is a shallow stainless disc, 10 cm across and about 2 cm deep, with a polished bezel and a ring of narrow slots cut around the rim. Those slots are not decoration. Air has to reach the movements for either needle to read anything, and a sealed case would tell you about the inside of the case rather than the room.

It hangs on one screw through a keyhole slot in the back.

Analog, so there is nothing to charge, nothing to pair, and nothing that minds being at 200 °F all afternoon.

• Temperature and humidity in a single 10 cm stainless dial
• Temperature 70 to 250 °F, humidity 0 to 100 percent
• Ventilated stainless case, polished bezel
• No batteries, no power, no electronics
• 10 cm across, 2.1 cm deep, as stated by the maker
• Keyhole slot on the back for a single screw