in/out port size is NPT 3/4 but this is accomplished with festo-assembled external adapter (as per our original requirements)
its main body internal thread is
still NPT1/2 so check out flow rate graph for NPT 1/2
connection as shown in photos above
note that external 3/4" NPT adapters can be field removed to return it to 1/2 NPT in/out if desired