WESTON MASTER II MODEL NO. S141/735
N° V 1576
PAT. N° 531996
WESTON MASTER III MODEL NO. S 217.3
N° K 5328
PAT NO. 531996
WESTON MASTER IV MODEL 745 SER.W
N° 109970
U.S. PATENTS 24637770
CAN. 411975
WESTON MASTER V MODEL S 461-5
N° A 9353