Not sure what exactly you may need but it includes a union. I've added their info and product page below. Side note the Cor 15 and 20 both do. I have three of them 2x 15's and a 20. Love the pumps. Pretty dang rock solid and built like a truck. The body is really well built.
Note from the page:
INCLUDED FITTINGS
The COR comes complete with all the fittings necessary for most aquarium configurations (0.75″ output, 1.0″ input). But we’ve also included a 1.25” union for the output so you can connect the pump in a manner that will result in the least amount of head loss. Plumb your main return-line in 1.25″ and get the full potential of the COR pump – as much as 50% or more flow!
Here is the product page:
INTELLIGENT, QUIET, ENERGY-EFFICIENT That's right, the COR-20 will run completely standalone OR connected to ANY Apex System via its AquaBus port. If you don't yet have an Apex, don't worry, down the road when you get one, you'll open the door to many more features (like mobile...
www.neptunesystems.com