Lifegard Aquatics ARP270855 Ball Socket Y-Fitting for Aquarium Pumps, 3/4-Inch Ball-Socket Tubing Allows The Hobbyist To Employ A Wide Variety Of Completely Customizable Return Line Configurations Each Socket Can Come Apart And Snap Back Together And There Are Y Fittings And Special Nozzles To Fit On The End Of The Assembly Measures 3/4-inch length