I was able to pull the old wheel off and then went to google on the computer and put in whirlpool dehumidifier. I was directed to a website where I could put in the model # of the appliancew and then was able to view pictures of repair parts. I was able to view the actual caster and determine that I was ordering the right one. The part came about 3 days later and I was able to snap it on without using any tools. There was alittle plastic guide to hold aside and slide the new caster in place.