Honeywell Strap-on Aquastat Controller , L6006C1018/U
Product Specs: https://customer.honeywell.com/en-US/Pages/Product.aspx?cat=HonECC%20Catalog&pid=L6006C1018/U&category=&rank=&v1=Sort.1.Product.Rank&asc=z Product Installation: https://customer.honeywell.com/resources/Techlit/TechLitDocuments/95-0000s/95-5973.pdf