Two female threads (1/4" NPT) with a centered male thread (1/4" NPT). Another hard to find fitting but it's expensive.
WARNING: This product can expose you to chemicals, including lead, which are known to the state of California to cause cancer and birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.
Review by Mark Osgood
Rating:
When possible I try to buy my brass fittings from Veneer Supplies. I find the quality of the brass and bronze to be far superior compared to what is available locally. Also combining the parts in Joe's vacuum pump instructions gives you the correct spacing for working with the 4" PVC. I've built three pumps using Joe's instructions and they all work perfectly.