WPB1901 brush is used for "cutting in". This is where you paint the corners at walls and ceilings and around baseboards and door/window trim etc. A paint brush is normally used to cut-in because it gives most control.
"Width: 1""(25mm)
For Oil-Based paint
Unique design plastic handle
Bristle length: 38mm
Thickness: 8mm
Packed by plastic bag"