Hi Johnie,
The Upgraded Replacement Coil Head for the Kanger ProTank -3 and AeroTank is not designed to work with the ProTank 1. For that tank, we recommend the coils in the link below.
http://www.smoktek.com/Replacement-Coil-Head-for-the-Kanger-ProTankProTank-2EVOD_p_679.html
Best regards,
Brad