Brand new in box Intel 265K processor. Bought for my brother's system, we ended up using an Intel 270K Plus due to his use cases for his PC.

The K means there is onboard graphics which can be a benefit for either workflow acceleration or debugging a GPU issue.

Most LGA1851 compatible motherboards will ship with a compatible BIOS already for the 265K. Check your motherboard BIOS # or check the motherboards you are going to buy to confirm LGA1851 socket, Core Series 2 "ready" for Intel, and if you will need to prepare a BIOS flash to get the CPU to work.