Whey isolate is whey protein filtered to remove most of the fat, carbs and lactose, so most scoops land at 25g of protein or more with very few carbs. It mixes thin and is a common pick when you're tracking macros.
We carry Dymatize ISO100, Isopure Zero Carb, Transparent Labs Grass-Fed Whey Isolate, Optimum Nutrition Gold Standard 100% Isolate and NutraBio, including unflavored options. See also whey protein and casein.