Duo. Litres incl. 1 pers: 315. Technical information:: Please note: In accordance with DIN 1986-100, a floor drain is required to protect the building against flooding, if a bath is installed without an overflow. No floor drain is required if ViFlow+ is used.. Not included in scope of delivery:: Push-to-Open valve and ViFlow+.. Colour on Demand (Quaryl®). Available from February 2018.