Excalibur DualFire Stringing Aid - Orange/Black - Change your strings on the TwinStrike easily with the use of the DualFire Stringing Aid. No need for a bow press! DIY string changes on the range or in the field can be accomplished quickly without losing valuable time. Works only on crossbows equipped with DualFire Technology. Change Your Strings Easily For Crossbows With DualFire Technology