Given the high volume of processors we manage, we don't fully clean off the thermal paste. Please be aware that your processor may have some thermal paste on it. A simple Q-tip and rubbing alcohol can help you clean it off. Exact serial #s will be shipped out.This product is a lot of 44 Intel processors, specifically a mix of i5 and i3 CPUs. All of the processors are from the Intel brand, ensuring quality and compatibility with a variety of devices. Whether you are looking to upgrade your current computer or build a new one, this lot of Intel processors offers a diverse selection of models to choose from.