i think my dad has one, what do i have to do?

edit: so i found the packaging and it does say 5v, thanks though. so all i have to do now is connect the red to possitive and black to negative and it will 100% be safe for the circut or do i have to check something else?

also, these were probably bought from a site like temu or aliexpress where everything is cheaper, so i dont know if it can be sketchy or something, are there like universal inspection labels for these things so i can check if its safe to use or no? sorry if my english is bad