Our company specializes in the production and sales, M16 M18 M20 M22 M24 type common and powerful protective sleeve M18 / M16 / M20 / M22 / M24 bolt extension sleeve | Long sleeve anchor bolt sleeves lengthened, M16 bolt sleeve lengthened , M18 bolt extended sleeve, M20 bolt extended sleeve, M22 bolt extended sleeve, M24 M16 anchor bolt sleeves lengthened lengthened sleeve Usage: Bolt extended (long) is designed for mounting sleeve anchor bar fastening nut is designed for measuring prestressed anchor bolt installation and ensure adequate prestressing. Can also be used to install or remove the nut deeper more complex kinds of machinery, electrical equipment.