Designed to target fish within a specific part of the water column by setting the upper and lower limits of depth. Rubber stoppers can be set at each end of the indicator holding it in one spot, or they can be spaced out to create a slip indicator system. A slip indicator system allows you to fish at extreme depths in lakes, and on streams it allows you to mimic an emerger rising to the surface by slowly lifting your rod tip. Eco friendly, Aero-dynamic, Made in USA. Installation instructions included. Each pack contains 3-Indicators and 6-Rubber Stoppers.