Oster Lemon Zester Grater with Channel Knife Oster Lemon Zester with Channel Knife. Lemon zester head features several sharp holes for zesting lemons, oranges and more. Channel knife is conveniently positioned in the handle. Channel knife and zester lets you create elegant garnishes and decorations with little effort. Comfortable grip handle. Large handle opening makes hanging easy. Ergonomically designed to fit the palm comfortably and softly. Lemon zester grater with channel knife is dishwasher safe. This lemon zester tool is durable and made with the high standards you can expect from the Oster brand.