2 Pack Replacement Filters for Titon HRV Q Plus 1, 1.25 1.35 Dimensions: 180mm x 270mm 2 Pack Replacement Air Filters suitable for: Titon HRV Q Plus 1 MVHR system (TP400A) Titon HRV Q Plus 1.25 MVHR system (TP406A) Titon HRV Q Plus 1.35 MVHR system Please note: these filters are own branded metal wire framed filters rather than plastic framed filters. They will have a slightly looser fit than the plastic framed filters but remain fully compatible with the units as per the manufacturers instructions. Titon Filter Product Codes: XP40032 XP46022 If you're not 100% sure which filters you need, we recommend you check the dimensions of your filters against the product description before placing your order.  Filters must be changed a minimum of every 12 months but this is subject to the environment in which you live. Filters being used in urban areas will need more regular changing, often every 3 to 6 months. Basic filter maintenance is recommended between filter changes. This can be undertaken by cleaning gently or vacuuming the filters. We recommend that you read your manufacturer instructions for detailed cleaning instructions. Typically you should avoid using any liquids when cleaning.Our filters are "own brand" filters of FilterMate and are in no way approved by or associated with Titon or any of its affiliate companies and brands.