The end of the long handle is a piston knob, which is used to fill the reservoir. Like "regular" brushes, you may use them painting either inside or outside. Suitable for sumi-e or Chinese brush painting or watercolor paintings, and good to work with watercolor half pans, watercolor pencils, soluble crayons or pastels etc.

This set comes with two kinds of bristles:
1. LG Bamboo and Orchid Wolf Hair Stiff Brush B30
This classic stiff hair brush is made of a blend of 90% weasel hair and 10% Rabbit hair(for better moisture holding). As it's name suggests, it is good for painting classical subject matters such as bamboo and orchid.
Brush Tip size: 1-1/4"L, 5/16" D; Brush Length: 8"

2. A Long-handled Goat & Wolf Combination Hair Water Brush C20:
It is made of 100% natural sheep hair. A very useful soft hair for washes using side brush strokes. In Chinese it is called Baiyun or "white-cloud" brush, which is suitable to paint flower petals, birds feathers, and other large scale color washes.
Brush tip size: 1-3/8"L, 3/8" D; Brush Length: 8 1/4"

*You may also order individually if you prefer. Please check it out.

**The brush is very easy to clean, just squeeze out some water and brush it on a paper towel.  Main care tip for the water brushes would be to clean and drain them before storing them when they are not going to be used for a while.

Related Article: How to use the Piston Filler Waterbrush?

Compared with squeezable barrel waterbrush or aquabrush: