About this 3D model

Updated 9-4-2019. Based on the comment below I took a look at the STL and realized the file had not been repaired before the STL was uploaded. It was done back in my Sketchup days 6 years ago. I just updated both parts in ANSYS Spaceclaim Engineer to include some things I learned over the years and to create smoother STLs. I also upload a STP file for anyone who wants to edit it. My brother has a pool vacuum that has several wheels held in place by two part clips. They keep breaking. It's a salt water pool. Replacements cost something like $15 for four of them. Being a captive market, they can get away with it. Not any more, I designed a replacement pin and retainer ring for him.