Casaneo Liner brush.
The Casaneo Liner brush carries a large reservoir of fluid in the Casaneo body, feeding it down a needle-sharp tip of Colineo synthetic, so you can paint metres of continuous line without lifting your brush to refill. This is the closest a brush comes to a refillable marker, and with advantages: you can easily change colours, there are no blockages, and the tip doesnt fail on rougher surfaces.
Size 6.

ABOUT DA VINCI
For three generations, Da Vinci, Germany, has created the highest quality artist and specialty brushes. Today, the family owned business offers the largest selection of artist brushes in the world. Each brush is crafted with pride to Da Vinci’s exacting standards. Using the finest raw materials available, skilled brushmakers draw on centuries old wisdom and input from contemporary professional artists. Using the latest technical innovations, they create brushes of unsurpassed beauty, quality and endurance.