Not required., Z861SB1: 90° flat duct bend horizontal., Z861SB2: 90° flat duct L vertical., Z861SI0: Adapter round flat., Z861SI1: 90° Adapter round flat., Z861SM1: Straight tube 500 mm., Z861SM2: Straight tube 1000 mm., Z861SS1: Connector sleeve (female)., Z92WWB1X6., Z92WWI1X6: Clean Air Plus recirculation kit., Z92WWJ11: LongLife recirculation kit., Z92WWM11: Installation kit remote motor., Z92WWY8X2: Mounting kit for seamless installation., Z93WWX1X1: Flat duct adapt.round 90° DN150 metal., Z93XXX1X1: Aluflex pipecyl. 150.