The Rotorvent opening unit enables hinged opening for the installed cowl to assist with access & sweeping purposes.
This is the opening unit only. The Rotorvent itself must be purchased separately.
In combination with Rotovent Unit Appears to work The units are well made and should last for years subject to chimney sweeps care and consideration.
(02/03/2015) B J Louch - SY25 6BS windy
Excellent Obviously not designed by an engineer. Really easy to assemble and instal. Took about 10 minutes