Use with 1/2 inch siphon hose.

From the Manufacturer:

All Fermtech Auto-Siphons have their valve mechanisms checked for proper operation!

The little flapper valve from the bottom fitting popped out. Can I fix it?
As long as one of the 2 small legs aren’t broken, this can be re-installed with a little patience. Here’s how:

– Affix the valve to the end of a long stick or dowel (2 legs pointing away from the stick) with some sticky tape folded over. Make sure the tape is more stuck to the dowel than on the flapper or you may end up with tape on the inside of your Auto-Siphon!
– Remove the Auto-Siphon center tube and insert the stick into the outer tube. Line up the legs with the 2 slots in the lower fitting and gently press in.