Viper Viperlock Aluminium Dart Shafts – inc O-Rings and Locking Pin – Black & Purple – Tweenie. These Viperlock Aluminium shafts are extremely durable and are available in 2 sizes and 6 colours. They include 1 locking pin and 3 o-rings per set. Each pack contains 3 shafts.Viper Viperlock Aluminium Dart Shafts – inc O-Rings and Locking Pin – Black & Purple – Short. These Viperlock Aluminium shafts are extremely durable and are available in 2 sizes and 6 colours. They include 1 locking pin and 3 o-rings per set. Each pack contains 3 shafts.