Excellent fit.
Helpful advice both in the web site and directly speaking to a technician who was able to answer the phone directly.
Might add a comment in general about using caulk specifically designed for hot tubs.
It was exactly what i needed(previous one cracked as i was replacing the heaters element) and the 1 day shipping option was amazing and good to know you guys offer that as a owner of a Plumbing company in MN if i get called to work on any spas I know just where to order parts