It depends on the cirumstances, if you have a pump you bought new between Feb 2009 and Nov 2011 and live in the US, then yes, we would need the model of the power supply, later and earlier ones included this jumper so if it was simply misplaced, you can order the jumper on our website. 6101.242 is for the 6101.240 power supply and 6105.242 is for the 6105.240 power supply.