Hellermanntyton conduit fittings with fixed external thread hgl s straight hellermann tyton 166 21603 the hellermanntyton 166 21603 hgl21 s is a straight fitting with an m20 external thread and belongs to the hgl s series this one piece connector has been manufactured from polyamide 66 pa66 the connector is highly resistant to solvents and oils and is supplied complete with a conduit seal and washer hellermanntyton 166 21603 hgl21 s m20 ip68 straight conduit fitting m20 167mm