Jienk Assembled Prototype Screw Terminal Block Shield Board Kit for Arduino MEGA 2560 R3: Amazon.com: Industrial & Scientific
Amazon.com: 4PCS Mini Nano V3.0 ATmega328P 5V 16M Mini USB Microcontroller Board with 4xUSB Cable Compatible with Arduino Nano V3.0 : Electronics
Amazon.com: OSOYOO Pro Micro 5V/16MHz Module Board with 2 Row pin Header Replace wit Pro Mini for Arduino : Electronics
Amazon.com: AITRIP 2PCS Type-C USB CH340 5V 16MHz for Nano Board CH340/ATmega+328P, Type-C Connection Compatible with Arduino Nano V3.0 : Everything Else
Amazon.com: KOOKYE 3PCS Pro Micro ATmega32U4 5V/16MHz Module Board 2 Row Pin Header for Arduino Mini Leonardo : Electronics
Amazon.com: RedTagCanada Pro Micro Atmega32U4 5V 16MHz Bootloadered IDE Micro USB Pro Micro Board Microcontroller Compatible to Arduino Pro Micro Serial Connection wPin Header (1, Pro Micro ATmega32U4 Micro-USB) : Electronics
Amazon.com: AITRIP 10pcs MH-Tiny ATTINY88 Micro Development Board 16Mhz /Digispark ATTINY85 Upgraded/Nano V3.0 ATmega328 Extended Compatible for Arduino IDE 1.0+ (OSX/Win/Linux) : Electronics