Seamless Fit: The rubberized tip is designed to easily slip onto any standard metal whistle without difficulty or modification. Lip Protection: The soft rubber material shields lips and teeth from harsh contact with hard metal whistles during use. Durable Design: Constructed from durable rubber that can withstand regular use while still providing comfort and protection. Color Options: Choose from a variety of assorted mix packs, colors, and hues. Easy to Use: Simply slide the flexible rubber tip guard onto any metal whistle in seconds for an instantly more comfortable whistling experience.