The USBasp is a really useful and quit inexpensive ISP programmer that suits AVR 8 bit microcontrollers.
This article offers some hints on buying and using the USBasp.
There are lots of sellers of these on eBay, Aliexpress etc… but there are traps in buying them. I recall buying the USBasp with cable for less than $5, but they are more like double that now… or more
The adapters with the pogo pins are simply ordinary adapters with P75-xxx (eg P75-LM2) pogo pins inserted. Continue reading USBasp – hints