OD of Quest is same size as 1/2" PEX
GO to Home Depot/Lowes/ACE hardware and get a 1/2" thread---push to connect elbow
Thread into WH Tank HOT out......cut connector on Quest Line OFF and Push the line into the elbow
OR take some measurements and add some 1/2" section of PEX out of elbow and connect that PEX to the Quest Pipe with straight push to connect connector
Just need to replace that Quest elbow with current available fittings....ask one of the employees for your options