Been there, done that about the wrong parts, haha. Its just a basic 1/4" Plastic T Fitting though, here's an example:1/4" Plastic T Fitting - 10 pk - 4068
You might want to run by an auto parts store and buy a new hose (7/32" inner diameter) to replace the old one. it'll only be a couple bucks and the ends will be tight on the fittings, compared to a 13 year old hose thats permanently streched. Just get about a foot of it and cut it to whatever length seems best. Not 100% necessary but it makes sure the hose stays tight.
Hope that helps!
edit: you'll need to have about a 2" piece of hose to connect the original nipple to the T-connector.