From the BCA website:
"If you have purchased a Tracker4 with a serial number starting with 21H05 (does not apply to Europe) or 21H06, please stop using the avalanche transceiver immediately and complete the form below to coordinate the return and replacement of your product.
To determine your serial number, open the battery compartment and remove the top AAA battery. You should see a barcode with the serial number underneath - make a note of the first 5 digits.
In the image below, the relevant numbers are "20H02", so this avalanche transceiver would not be affected. According to the BCA Instagram page, affected devices will be replaced free of charge.
Link to the recall form
