Here are Four unusual porcelain spools by New Zealand Insulators (NZI) as follows:

Very cool large spool (5 inches tall) - incuse marked MADE IN / NEW ZEALAND / 1954

Another unusual spool (4 inches tall) - inkstamped NZI in a circle

Next spool is also 4" high inkstamped NZI / 1970

Last spool is incuse marked NZI / 69

Take all four for $25 plus actual postage.