I'd like to buy a second-hand Bangle 2. Am happy to pay for watch and packaging costs up to maximum of £55. I don't know the magnetic field from the charging cable. Field strength and packaging guidelines for Royal Mail can be found here. https://www.postoffice.co.uk/mail/what-can-i-send. @Gordon may know if the field strength means that it's OK to post via Royal Mail.
Please DM me if you would like to sell me a Bangle 2. Thank you.