Thermostat arrived just as ordered. A little late but that was just proof that Postmaster Dejoy's effort to slow down the mail was working. Put back together easily. Original thermostat had pigtails but replacement had terminals. Crimped and soldered spade connectors on jumpers from terminals to line and load wirenuts. Set up thermostat using built-in set-up program. Easy Peasy. Floor heating beautifully. Now all I have to do is get that rats' nest of wires back into an 18-cu in. box. Mission impossible. I'm gonna need a bigger box. The saga continues. Boiled down. Warm Your Floor did a great job. Thanks, guys.