A:Answer Hello, thank you for your question. When the model is manufactured, these extra letters/numbers are placed on the appliance rating plate and product registration card. These letters/numbers are used to identify manufacturing specific data when the appliance is made. Should service or parts be needed, these are used as identifiers for the specific appliance. While shopping online, you will primarily see model numbers listed without these identifiers - in this case, JVM6175EKES. When you purchase and receive your unit, the numeric identifier will be listed in the model number on the rating plate. If you are looking for a specific version of an appliance, you would need to speak to your local Best Buy to see if they are able to provide you with stock information. Rest assured, though, any JVM6175EKES microwave will be functionally identical to JVM6175EK5ES. We hope this helps! -Chris@GEA