Amazon.com: Geekstory for ATMEL 51 AVR USB ISP ASP Microcontroller Programmer Downloader with Cable + 10Pin to 6Pin Adapter Board for Ender 3 or Ender 3 Pro : Electronics
Amazon.com: KeeYees 2pcs Downloader Programmer for USBASP for ISP with Cable and 10Pin to 6Pin Adapter Board for 51 for AVR Series Microcontroller : Electronics
Kanda - Atmel AVR ISP adapter with 2.0mm pitch
AVR-ISP Pogo Pin Adapter (2x5 IDC,2x3 Pogo 2.54mm) from Pnoxi on Tindie
Kanda - Atmel AVR ISP adapter with 1.27mm (0.05inch) pitch
Pololu USB AVR Programmer v2.1
AVR-ISP-MK2 - Open Source Hardware Board
4pcs AVR ISP 6 Pin to 10 Pin Adapter | Open ImpulseOpen Impulse
1PCS 10Pin To 6PiN Convert To Standard 10 Pin To 6 Pin Adapter Board For ATMEL STK500 AVRISP USBASP ISP Interface Converter AVR - AliExpress
10Pin To 6 Pin Adapter Board+ USBASP USBISP AVR Programmer USB ATMEGA8 ATMEGA128 ATtiny/CAN/PWM 10Pin Wire Module DIY - AliExpress