Connect concentrator modules to Raspberry Pi using the RAK2287 Pi HAT – RAKwireless Store
Power Over Ethernet (PoE) HAT for Raspberry Pi 3 B+ 4 and 802.3af PoE
SparkFun Qwiic HAT for Raspberry Pi - DEV-14459 - SparkFun Electronics
Home Automation 8-Layer Stackable HAT for Raspberry Pi – Sequent Microsystems
Pmod HAT Adapter for Raspberry Pi
Power over Internet(POE) Hat for Raspberry Pi 4/3B+
OAK-FFC RPi Hat – Luxonis
Cluster HAT Kit (includes 4 x Raspberry Pi Zero W)
Rpi HiFi AMP Hat – Raspberry Pi|Industrial Camera|USB TO CAN FD
Amazon.com: 2-Channel Isolated RS232 Expansion HAT for Raspberry Pi 4B/3B+/3B/2B/B+/A+/Zero/Zero W, SC16IS752+SP3232 Dual Chip Convert SPI to RS232 Data Rate up to 921600bps Embed Multi Protection Circuits : Electronics
$49.80 - Gameboy Style Gamepad Hat for Raspberry Pi - Tinkersphere
CaribouLite RPi HAT | Crowd Supply
Rpi HiFi DAC Hat – Raspberry Pi|Industrial Camera|USB TO CAN FD
RPI Level Shifter Hat from chris.design on Tindie
pi.ka – FPAA rPi HAT - Okika Technologies
Raspberry Pi PoE+ HAT - PiShop.us
Raspberry Pi Sense HAT - Adafruit | Mouser
Raspberry Pi A+/B+/Pi2/Pi3 Prototyping HAT (RPi-Proto-HAT) - Watterot
IO Expansion HAT for Raspberry Pi 4B/3B+ - DFRobot
Raspberry Pi Sense HAT | Elektor
Top 20 Raspberry Pi HATs & Shields You Should Try - Latest Open Tech From Seeed
The 10 best Raspberry Pi HATs — The MagPi magazine
The Top 10 HATs and pHATs for Raspberry Pi
RS485 CAN HAT for Raspberry Pi 4B/3B+/3B/2B/B+/A+/Zero/Zero W/WH,Allow Long-Distance Communication via RS485/CAN Function Onboard CAN Controller MCP2515 via SPI Interface Transceiver SN65HVD230
Innovate with Sense HAT for Raspberry Pi (E-book) | Elektor