About this door bottom seals & brush strips
Stormguard 838mm Brown Bottom-of-Door Brush Strip
Colour matters with a screw-on strip, because it is fixed on the visible bottom edge of the door. A white strip on a dark brown door looks like a stripe. This Stormguard strip is brown, so it almost vanishes against a stained or dark-painted door, which is the reason to pick it over the white version.
It is 838mm long, which covers narrower internal doors, and it can be cut shorter if the door is smaller still. Pre-drilled holes make marking out easy, and the fixings are in the pack. The bristles seal gaps up to 15mm, so it is aimed at moderate gaps rather than a very large one.
Because the gap capacity is 15mm, check your gap before ordering. If it is larger than that, the 25mm Stormguard strips are the better choice. Hold the strip against the door with the bristles just touching the floor, mark the holes, drill and screw.