I am offering this unusual insulator as a trader for your better CALIFORNIA insulators. It is a clear glass battery tray that works just like a battery rest, i.e., collects leaking battery electrolytes and provides insulation. Don't know why it isn't listed in the McD price guide. Embossed "E.S.B. Co. No 3", it is 9" x 9.75". The squarish dimensions I understand are unusual as the rectangular ones are more common. The feet are factory-grinded. There are two flakes in the upper left-hand corner and a couple other nicks here and there. SOLD at Mountain View Show 2002.