Tombow Dual Brush Pen - N00 - Colorless Blender
Each pen has a flexible brush tip and a fine tip in one marker. Brush tip works like a paintbrush to create fine, medium or bold strokes; fine tip gives consistent lines. The colorless blender Brush Pens are ideal for artists and crafters. The water-based ink is blendable and the resilient nylon brush retains it's point stroke after stroke. The tips self-clean after blending. Acid-free and odorless.
This pen doesn't actually blend 2 colors as it actually lifts some of the ink from one color to make a lighter shade of the color. Excellent for shading