10 Gallon Seat Top Cooler by Igloo. UltraTherm Insulation, Impact Resistant, Reinforced Handles, Stackable. Flat Lid is pressure fit (not threaded). Since the lid isn’t threaded, you can fit a temperature probe underneath [See: Hands On: ChefAlarm Thermometer].
I use this same cooler for my mash tun and it has worked great for me for years. It holds temperature very well and it has held up like a champ. It would also make a good HLT.
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