Have a next in my wrist
Couple things
There are several devices you could use but it comes down to either a proxmark3 or a China blue cloner
The proxmark let’s you get into the nitty gritty, but is dangerously close to coding, and hurts my brain at times will work for 125khz and 13.56mhz
Expensive… unless you get the “easy” version which has its own draw backs
The blue cloner is 2-3 buttons, read/write
But it doesn’t work on every version of 125khz
But it does work on the most common 3
It places a password on the chip after it writes, but If all you use is the cloner, the cloner knows it’s own password which is something commonly known like 1234567890
Very cheap
The blue cloner gets some flak because the t5577 side of the next doesn’t have tear protection, meaning if you hit the write button and move to early, it won’t write everything correctly, and can semi or fully brick your chip
There is a mod I plan to copy, where the antenna is reorientated to get better coupling to the chip
Important thing to note, you will only be able to use 1 ID per side of the next, so 1 125kz uid and 1 13.56mhz uid
If you have more than 1 of each system you will need to enroll the uid into each system
In regards to the 13.56 side, you can do a lot of programming from your cellphone since most are nfc compatible but there are some cellphones that lack nfc (old)
I mean, if you have a device (besides the blue cloner) that can write… more than likely it can read
So you could just read the chip info to see if it looks correct
… but there’s only one 
way to really know lol
Stick your hand in front of a reader lol
