Builder's Best UL 181 Flexible Foil Ventilation Duct, 4" x 8', Aluminum/polyester Sink Basket Strainers Designed to fit with 3-1/4'

Designed to fit with 3-1/4' x 10' or up to 8' round duct for flexible installation

Aggressive tip angle for fast cutting

even in the tightest of spaces

and for all temporary lumber construction

Builder's Best UL 181 Flexible Foil Ventilation Duct, 4" x 8', Aluminum/polyester Sink Basket Strainers Designed to fit with 3-1/4'This wire helix product features steel wire support with a multi ply design of metalized polyester and aluminum polyester laminate. It is UL 181 listed and labeled as a Class 1 Air Connector. UL 181, Class 1 air connector label Multi ply design of metalized polyester and aluminum polyester laminate Steel wire support 3 dia. has pitch 412 dia. has 1 pitch UL sticker every 10 feet Maximum velocity rating 5000 fpm