Dynamite Li-Po Glow Driver Igniter HOW IT WORKS!!! Disassembly Inspection

I wanted to know how my my new Dynamite glow plug igniter works. I think when it senses a glow plug it steps down the voltage to 1.2V. with just the multimeter connected its putting out 4.2V. By far the most sophisticated igniter I've seen so far. DYN1926
https://www.amazon.com/gp/product/B003O7IGC0/ref=as_li_tl?ie=UTF8&tag=fintechcomm0f-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B003O7IGC0&linkId=ce4e6e7657ecb6ff60f5b6dc242d19d9