The machine has a reservoir (tank) holding cooking oil; capacities vary — common sizes are 20 L, 50 L, 100 L, and even up to 200 L in some setups.
A user (or shopkeeper) enters the amount of money the customer wants to spend (or the amount of oil desired) using a keypad/controller.
The machine pumps out the correct quantity of oil into the customer’s container; flow sensors + a controller ensure accurate measurement (as little as ~ KSh 10 worth).
Many Oil ATMs support modern payment methods (e.g. mobile money / cashless), not just cash.