Blackheart Crossbow String 31.75in TenPoint. These bowstrings feature GlideLock center serving which enhances durability reduces friction reduces serving separation and almost eliminates the ridges between the serving strands. The DuraWeave process includes pre-stretching the strands resulting in highly consistent string length. Each string is meticulously hand crafted to fit your crossbow. 26.125 for Excalibur Micro 335 Micro 335 Nightmare. Specifications for Blackheart Crossbow String: Manufacturer: Blackheart Color: Black Package Contents: Blackheart Crossbow String Blackheart 1601835: Crossbow String 31.75in TenPoint