1 1/2" tri-clamp to 1/2" barb fittings. I just found a guy on Ebay who has them for $8.90 plus $2.90 shipping. St Pat's is the cheapest I've seen elsewhere for $13 each plus shipping.
No affiliation, just sharing the love Just bought 4 for myself.
glacier tanks has them for $8.90 as well...
Kegged: Amarillo Ale, Edwort's Apfelwein, Golden Dragon, 1554, 888 RIS
It's the same vendor - the Paypal payment went to Glacier Tanks.