Abstract: A capping channel for a glass sealed unit adapted to be surrounded by a layer of polysulphide sealant. The channel comprises a rigid U-shaped member made of a thermally non-conducting polyvinyl chloride compatible with the polysulphide sealant. The member comprises ribs projecting from the inner surface of its base and adapted to penetrate in the sealant for increasing the retention of the channel to the unit. The ribs are set by pairs to form a V-shape and are provided with a lip extending from the free edge of the ribs, each lip of the pair being directed towards each other.