From the terminals to the casing, the Space Age Electronics build looks dependable and gives a reassuring click when engaged.
RESIDEO HONEYWELL L7224U1002 Oil Electronic Aquastat Controller 120V
The Honeywell brand is a nice touch, and you will find that it suits many electrical setups.
You will find that Features is N/A, which keeps the buying decision centered on the relay itself.
A nice touch is the White-Rodgers logo, which is printed clearly enough to read without any trouble.