Special 3 to 1 high shrink rate heat shrink tubing is the perfect choice for securing servo and extension connectors. Each 2" piece of 3 to 1 heat shrink tubing shrinks to form a lock around the connector making it impossible for the connector to unintentionally be disconnected. Also, helps to seal against fuel and oil for exposed wiring and connectors such as gyros and tail rotor servos. Special 3 to 1 heat shrink tubing can also be used to capture important information concerning servos or connections. Simply write info on white 3 to 1 heat shrink tubing using a fine line marker. Special heat shrink tubing require only heat available from hobby type covering heat guns for shrinkage.