It is in snail mail since purchased,it has been sitting in NYC,for a week,according to tracking.When they do arrive ,they send three,each has a different size hole.Instructions say try the middle size first,then either go bigger or smaller if you,are wanting to hone in on what works best.SO,it is experimentation.In the meantime I popped in a180degree thermostat,since I am waiting.I could not find a Colorstat ,(not at RockAuto for my appplication),and that seems to be the best one ,everyone agrees.I am using a Autorad 180 Ultraststat,in the meantime.While ordering at RockAuto,I accidenty also,purchased a 'Failsafe 180',and kept it,but they always fail,I heard.I can't be bothered sending it back however.[I think Autorad has bought every AFTERMARKET thermostat manufacturer BUT Colorstat,and that is why Colorstat is better/it's not made by Autorad]. HOWEVER, it still works after a week .I'd suggest buying yourself the restrictor plates ,in the meantime,they are very reasonably priced.You are living in the USA,you don't have to worry about exchanging Canadian $$$ to American currency .They were 20 bucks USD,free shipping USPS.Cheaper that McDonald's take out meal for 2 with a coupon....IMO.
ALSO, because if you order yours as well ,USPS, you'd get them before I do,since mine seem to be stuck,waiting to cross into Canada.