Plantronics Encore Pro Headset Models HW291N and HW301N Date Codes Encore Pro Headset Models HW291N (re-numbered HW710) and HW301N (re-numbered HW720) date codes The date code is under the ear cushion and is represented by three numbers for the month and year. In the example below, 9-08 stands for September 2008. Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Comment * Name * Email * Website