The resonator body 1, wherein {HEAD ~ the abutting edges} include {TAIL ~ undercut portions}, wherein the undercut portions of the abutting edges engage into each other so as to be locked together 
The resonator body 1 , wherein { HEAD ~ the abutting edges } include { TAIL ~ undercut portions } , wherein the undercut portions of the abutting edges engage into each other so as to be locked together
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH