Any metal thermometer that is designed for that temperature range. Check it's accuracy with boiling water. My digital is 2 degrees low not that that would mean much but they can be off by a lot. No big deal as you know what to add or remember what temp that thermometer works best at plucking. You've got to be 155 F or it's a losing battle. I get the water 155-160 F and dunk, swish, lift and repeat until the largest feathers pull with no effort what so ever.