Just one of many YouTube channels explaining Meshtastis
Just one of the places you can buy one from https://store.rokland.com/products/wismesh-tag-from-rakwireless-mokosmart-meshtastic-compatible-card-sized-node-us915-mhz/?ref=km4ack.
Full transparency this an affiliate link same price of $50.00 as on their website but a % goes to a club member. So if you plan on getting one why not support a club member.
https://www.youtube.com/watch?v=ZsIWyVzqJPM&list=PLshzThxhw4O5JTOACGHzYSSd3soDhoXKK
