Does it matter which side of radiator flows & returns?
Brugman Universal Radiator Uni 6 Profile Type 600 x 1000 mm Compact Radiator Valve Radiator Including Bracket and Valve Insert 6 Connections (600 x 1600 mm Type 22) : Amazon.de: DIY & Tools
600 x 1800 mm White Straight Middle Connection Bathroom Radiator Towel Warmer Hand Towel Dryer Design Bathroom Radiator : Amazon.de: DIY & Tools
Luxury White Traditional Cast Iron Style High BTU Four Column Horizontal Electric Heated Radiator Rail Central Heating Radiator for bathrooms, Kitchen and Rooms Dual Fuel Column Radiator Colona : Amazon.co.uk: DIY &
Bathroom Radiator Straight White with Standard Connection 1160 x 500 mm : Amazon.de: DIY & Tools
Heilmetz Design Radiator Anthracite Oval Vertical Panel Radiator 1800 x 600 mm Heating Centre Connection Double Layer Living Room/Bathroom Radiator : Amazon.de: DIY & Tools
Flat plate for radiators (H x W) 600 x 1800 : Amazon.de: DIY & Tools
Meykoers Designer Radiator 600 x 1800 mm Middle Connection Single Layer Anthracite 1093 Watt Tube Radiator Horizontal Heating Radiator : Amazon.de: DIY & Tools
Compact central connection radiator with valve type 33, 500 x 1200 and bracket and valve : Amazon.com.be: Tools & Home Improvement