This is a COIN SLOT BLOCK for your Duncan parking meters mechanical mechanism.
This Coin Slot Block was used on the model 60 and later, mechanical mechs and will not fit the earlier model 40 and 50 mechanical mechs. Please take a look at the pictures and see if this is what you need for your meter.
You are bidding on the Coin Slot Block in the first picture, ONLY. The other pictures are to show you what and how it should fit.