Irritrol Rain Dial Outdoor Ext Replacement Key

Irritrol R8969 rain dial outdoor ext replacement key to be used on rd600-ext-r, rd900-ext-r, & rd1200-ext-r irrigation sprinkler controllers box.

Why spend $6 on this one?

https://www.amazon.com/Irritrol-R8969-Rain-Outdoor-Replacement/dp/B00ODAP0US/ref=sr_1_1?ie=UTF8&qid=1526063077&sr=8-1&keywords=rain+dial+external+key