Knauf Insulation Jet Stream® Fiber Glass Blowing Insulation is an unbonded, virgin fibrous glass blowing insulation designed with optimal thermal properties and excellent coverage and blowing characteristics. Knauf Insulation Jet Stream Fiber Glass Blowing Insulation is installed in open attics of both new and existing structures and/or in closed cavity applications with the BIBS system (Blow-in-Blanket System) in which ventilation is not required. Jet Stream, when used in closed cavity applications is BIBS approved and can only be installed by BIBS certified installers to ensure the highest quality installed performance. Loose fill blowing insulation is intended for use where pneumatically installed insulation is most cost-effective.