There are 4 diameters of this painting tool: 15mm, 18mm, 21mm, and 25mm. These professional painting brushes can meet your different needs. The handle is 8.3 inch long allowing to paint more area at one time. The bristles are made of synthetic filaments, soft and high elasticity, and do no harm to your objects. It's with medium stiffness, ideal -based , glue, , gloss, and semi-gloss paint. The synthetic filaments paint uniformly and make a surface. They can hold more paint so as to time. The brush handle is made of solid wood and they're ergonomically designed. It subtly increases friction and prevents falling. There's a big hole on the top of the brush, it allows you to tie a rope or directly hang up. The brush is designed with sturdy stainless steel ferrule, which firmly keeps all bristles with no bristles falling. The edge paint brush features round tapered tips. It fits perfectly for small spaces and painting those detailed areas where edges meet. They're great choices for painting cutting in, touch up, baseboards, stair railings, sash, etc. Also good as a duster for keyboards and other stencils. size: Diameter about 15/18/21/25mm Material: Wood colour: as shown Package Contents: 4 x paint brushes Only the above package content, other are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.