McElroy has initiated a Technology Upgrade Program that will allow you to receive a $500 credit towards the purchase of the new DataLogger 6 when you trade in your DataLogger 3, 4 or 5 units. Act now by emailing firstname.lastname@example.org and providing the serial numbers of your DataLogger units. The units you are trading in must include the computer, transducer, charger, cradle and case. Contact your McElroy Senior Account Manager for more information. This offer ends on Dec. 31, 2017.