All draft beer faucet handles and faucets manufactured for the U.S. market have the U.S. beer industry standard 3/8"-16 UNC threads.
Those manufactured for markets outside U.S. have a European metric thread specification.
This means that faucet handles with European threads will not fit faucets with U.S. threads, and faucet handles with U.S. threads will not fit faucets with European threads. However, all faucet handles and faucets produced in the U.S., even if made by different manufacturers, are interchangeable as they have the U.S. beer industry standard 3/8"-16 UNC threads.
Currently there is no adapter piece available for fitting handles with European threads to faucets with U.S. threads or vice versa.