Amazon.com: USB AVR Programmer w/ 6-Pin 10-Pin IDC ISP Connector for USBASP : Electronics
10-pin to 6-pin AVR ISP [I106] : ereshop, ereshop.com by ERE Company Limited.
Equinox Products Page - ISP Header OVERVIEW
10-Pin Convert to 6 Pin Adapter Board For ATMEL AVR ISP Programmer USBASP STK500 | eBay
In-system programming - Wikipedia
10 Pin To 6 Pin Adapter Board Connector For ISP Interface Converter AVR AVRISP USBASP STK500 Standard
10 Pin Convert To Standard 6 Pin Adapter With 5v Usbasp Isp Avr Programmer Case - Integrated Circuits - AliExpress
Batsocks - AVR ISP Header Pinouts
AVR ISP 10P to ICSP 6P Converter - ElectroDragon
10 pin ISP Male Connector Header – Flytron
Amazon.com: HiLetgo USBTiny USBtinyISP AVR ISP Programmer 6/10 Pin Bootloader for Arduino UNO MEGA : Electronics
AVR ISP Pinout
5pcs 10 Pin To 6 Pin Adapter Board Connector ISP Interface Converter AVR AVRISP USBASP STK500 Standard Geekcreit for Arduino - products that work with official Arduino boards