Many people say the GE relay swaps right in, so there is little downtime.
Enclosed Fan Relay for Heating /Cooling Applications, General Purpose Switching
What stands out about this relay is the WAGO brand, so I know who to contact for documentation.
What stands out about this listing is the Features entry reads N/A, which keeps the page clean.
A nice touch is the gentle click sound this unbranded relay makes, giving clear feedback when it switches.