It is a Bi-Metal t'stat and mechanical. Yes, it can be tweaked if it's too tight.
Weber WSM, Weber GA, Weber Spirit S-320
Charbroil Oilless Turkey Fryer
Wife LuzziAnn 1956 model.
Maverick ET-732, Superfast LSU Purple Thermapen
The Fun Never Stops at the BBQ Brethren Throwdowns
2013 Throwdown Grand Master. 1/2 of Team Paradise.