These are the through-hole pads for the rotary encoder. There are 5 small pads for the rotary encoder pins, and two larger pads for the tabs.

The rotary encoder is available in CircuitPython as board.ROTA, board.ROTB, and, if applicable, the push button is board.SWITCH.

The rotary encoder is available in Arduino as PIN_ENCODER_A, PIN_ENCODER_B, and, if applicable, the push button is PIN_ENCODER_SWITCH.

On the end of the board, opposite the USB connector, is a capacitive touch pad.

This pad is usable in CircuitPython at board.TOUCH, and in Arduino at PIN_TOUCH.

On the skinnier end of the board are the four pads that make up the USB connector. Plug directly into a USB A port to use the Rotary Trinkey.

On the back of the board, in the center towards the touch pad end, is a tiny RGB NeoPixel LED.

This LED is controllable in CircuitPython at board.NEOPIXEL, and in Arduino at PIN_NEOPIXEL.

Towards the center of the board is the SAMD21 microcontroller. This is the brain of the board.

The button on the back of the board is the Reset button.

Tap once to reset the board. Tap twice to enter the bootloader (needed for installing CircuitPython).

There are three debug pads on the back of the board. The top one is clock, the one below it is data, and the one near the reset button is reset.