Singing Rock Worker Slings 150cm/60. Available in four lengths and are made of the highest quality materials out there. Individual instruction sheets attached. Specifications for Singing Rock Worker Slings: Manufacturer: Singing Rock Length: 60 in Quantity: 1 Color: Black Breaking Strength: 22 kN Features of Singing Rock Worker Slings: Strength: 22kN CE 1019 EN566 EN795B EN354 Package Contents: Singing Rock Worker Slings The Singing Rock Worker Slings is a quality addition to the Singing Rock lineup. For more great deals on Runners & Slings by Singing Rock please browse our Singing Rock Climb page.