Just fyi, the device at that link is currently showing $9.62 for a single unit, once logged in and the one-time-only "Welcome deals" are eliminated. But AliExpress pricing can vary hour by hour based on seller, inventory, algorithm, RNG.
I got the one that’s white with a bit of red near/under the cap.
One other thing that took me a bit to figure out: after removing the cap, the entire back of the device slides off (kind of like a battery cover in a remote) and there is a spot to put a SIM card beneath. Supposedly this does GPS too but I haven’t figured out how yet.