Most heater connectors come with both ends attached: an E/O for the external wet connection and a female Santi connector for the undersuit side.
Generally people either buy:
A Santi heating connector (there's many others like this) which goes under your existing drysuit inflator valve. This sticks out a bit but works very well (I prefer this with thick winter gloves and it's cheaper)
Santi Drysuit Connector connects Santi Heated Vest, Gloves or Undersuit to the battery using your drysuit inflation valve on top of the unit.
www.dirdirect.com
Santi Drysuit Connector Specification Drysuit inflation valve connector with the function of integrating the connection to the battery with a voltage not higher than 12V. The connector takes an external standard E/O cord through a standard suit inflation valve and provides power connection from...
scubadivinggear.uk
Or a new "Thermovalve" such as these which replaces the existing valve; so one for summer, one for winter.
Low-profile Santi Thermovalve 303 fully replaces the drysuit inflator valve. Innovative connection for heated undersuits, vests and gloves.
www.dirdirect.com
Ammonite System 360 T-Valve for Heated Suit Systems 360 degree swivel head T-VALVE can rotate a total of 360 degrees allowing for a wide range of hose configurations – thus, it truly doesn’t matter in this case if one rig routes the drysuit hose under the right arm and another – under the left...
scubadivinggear.uk
SF Tech Heating Valve Specifications Low profile, the SF Tech heating valve is constructed to be flatter than a standard inflator while providing E/O connectivity for a heating system. Made of Delrin, a material with excellent impact resistance, the valve is extremely robust and durable...
scubadivinggear.uk
Please note that the Santi cables are crap and will break after a year or so. You then replace the cable with the stronger cable which is coaxial (that's the one in the Ammonite connector). These are MUCH better than the weak Santi cables. (I'm pissed off with replacing these cables every year; finally found a source for the MUCH better coaxial cables which has a bigger current capacity, i.e. less voltage drop than the Santi)
The replacement task is pretty easy but needs a soldering iron. Also, Santi, bless them, glue their undersuit connector together so you'll need the replacement to solder the cables to.
Heating System E/O Cord Super strong. Having problems with your heating system E/O cord, then try the new coaxial cable. Extremely durable and tolerant of
www.rebreatherpro-training.com
Deep Ideas Heater push lock connector [chogori mini] - Yellow male Chogori connectors for drysuit and heated garmets
deep-ideas.co.uk
They will even do the job for you for a small fee.