Description:
Analog hygrometer, which is just suitable for very small formicaria.
The fixture in a 27mm hole is drilled through the Formicaria plug 27mm with a 22mm hole.
Otherwise, the thermometer can stick with a double-sided adhesive tape (not supplied) on the formicaria backside.
Note:
Close never the hole on the backside of the hygrometer, because you can get a measurement errors