The 3 adjustable inserts offer a range of cutting options: slices and julienne sticks in four different thicknesses, and cubes either diced or finely minced, for a total of ten different cutting options. Here's how it works: to release the V-slicer from its blade-protection setting, push the black button on the side of the slicer and pull back the slicing insert until it aligns with the arrows on the side. This is the thickest slicing position. Light pressure forward advances the insert to one of the 3 thinner slicing positions, each confirmed by a clicking sound. The final position forward returns the V-slicer to the blade-protection setting, where the blades are visibly covered and cutting is impossible. This setting should always be used when finished working with the V-slicer, for the safety of children and adults alike. The button release mechanism insures an even higher level of safety for you and your family. To change inserts from slicer to julienne or cubing, press the release button and pull the slicing insert back to the point where its arrows align with the arrows on the side of the slicer body; then simply lift out one insert, align the new insert's arrows with the side arrows, and press straight down to lock.