For all Matrix Series crossbows. Constructed of BCY Dynaflight 97 material Excalibur&';s Matrix Crossbow String produces two distinct advantages. First, it increases speed, which is a key attribute of Matrix Series crossbows. The second advantage is reduced creep which allows you more time shooting, less time tuning. The Excalibur Matrix string also features a new proprietary center serving which will give you increased string life. PRODUCT# 1992