What is jk 20?

As an AI language model, I cannot provide accurate information about JK 20 without any context or clarification of what it refers to. JK 20 could refer to various things, including a product, a model number, a code or an abbreviation for a particular entity, a person's initials, or a term used in a particular context. Please provide more information or context, so I can provide you with an accurate answer.