Designed to contain an EEEKIT hygrometer from Amazon in the bottom: https://www.amazon.ca/dp/B07JMXL6K5?psc=1&ref=ppx_yo2ov_dt_b_product_details
Insert hygrometer in the bottom and give it a 1/4 turn to lock it in.
Print in Transparent filament so that you can see the colour change of silica gel such as: https://www.amazon.ca/dp/B09QFJQQ7Q?psc=1&ref=ppx_yo2ov_dt_b_product_details
This is designed to stay with your filament rolls when mounted in the Bambu Lab AMS unit to ensure that your filament is dry. In addition, keep it with your unmounted filament, stored in zip-lock bags so that when you go to use it to print, you can be assured that your material is dry.