Summary

Glow plug heater for parkside batteries. With additionnal 12v output for gas pumps or whatever.
you need 2 DC converters like this : https://fr.aliexpress.com/item/32711173698.html
One is modified to connect an external potentiometer (unsolder the potentiometer that set the current and solder wires to external 10kohm potentiometer) and set the voltage potentiometer in order to have a 1.25-1.5V output

jack plugs : https://fr.aliexpress.com/item/1005004654096753.html
male connectors : https://fr.aliexpress.com/item/1005002765359666.html
M3 inserts : https://fr.aliexpress.com/item/1005004535859664.html
amperemeter : https://fr.aliexpress.com/item/32752632752.html
10kohm potentiometer : https://fr.aliexpress.com/item/1005003680612700.html