Truma Spare 46010-03 Ultraflow Filter HSE Conversion Kit (20 ratings) £84.50 Quantity: at £84.50 each Add To Basket 6 in stock. The Ultraflow Conversion Kit allows you to convert your existing filter or compact housing system without having to replace your pump assembly. A more cost effective and practical solution for those who want a reliable replacement for their Crystal system or an alternative system. Now you can convert your existing filter or compact housing without having to replace your pump. Available in white.