"ULTIMATE ADJUSTABILITY"- THAT IS A TERM WE LIKE TO USE WHEN DESCRIBING THIS INDICATOR AND IT IS PROBABLY ONE OF THE MAIN REASONS IT IS A BEST-SELLER. THE SLIT IN THE SIDE OF THE INDICATOR MAKES IT EASY TO PUT ON THE LEADER (EVEN WITH A FLY ATTACHED) AND THE FLUORESCENT GASKET SECURELY LOCKS IT IN PLACE. ADJUSTING THE INDICATOR IS AS EASY -- GRAB IT FIRMLY AND SLIDE IT INTO THE DESIRED POSITION. THE FOOTBALL SHAPE MAKES FOR EASY TO SEE EVEN IN HEAVY RIFFLED WATER. AVAILABLE IN 4 SIZES AND 5 COLORS. 4 PER PACKAGE. INSTRUCTIONS INCLUDED.