AVR ISP Shield Burning Burn Bootloader ATmega328 Programmer for Arduino UNO R3 | eBay
Amazon.com: OSOYOO Pro Micro ATmega32U4 5V/16MHz Module Board with 2 Row pin Header Replace with ATmega328 Pro Mini for Arduino : Electronics
SOLVED: Attiny13A Use pins 5,6,7 with Arduino UNO as programmer - Avrdude, stk500, Bootloader issues - Arduino Forum
Installing an Arduino Bootloader - SparkFun Learn
ATmega328P Wearable Development DIY Board + CH340 USB to TTL Programmer Module + 6 Pin Cable Compatible for Arduino|usb to|usb to ttlusb to ttl ch340g - AliExpress