The kit includes a comprehensive selection of collets—Steel expander 1 5/8″ – 2″, 2″ – 2 1/2″, 2 3/8″ – 2 3/4″, 2 3/4″ – 3 1/8″, 3 1/8″ – 3 1/2″, 3 1/2″ – 3 7/8″, and 3 7/8″ – 4 1/4″—allowing for a versatile expansion range tailored to your specific needs.