About the Design:

The Tokens are slightly smaller than a canadian dime ( 18.03 mm)
The tokens used prior to 1954 were brass coins. In 1954, the year the city's first subway opened, these were replaced by lightweight aluminum tokens produced by the Royal Canadian Mint.
The new tokens were simply designed with the word "SUBWAY" prominently displayed on both sides.
By 1966, a new brass token was introduced for single-token sales. The brass token used a more elaborate design displaying the TTC crest on the obverse and the TTC logo on the reverse.The replacement for the 1954 and 1975 tokens was a bi-metal design phased-in starting in November 2006. It replaced the old tokens completely in February 2007