Just stack, pack, and be ready when inspiration strikes with the rich, opaque watercolours in Koh-i-Noor's Watercolour Wheel Stack Pack! The Watercolour Wheel features 24 pans housed in four durable, interlocking trays that neatly stack and easily pack away. The plastic trays lock and unlock with a simple twist letting you dial 144 different combinations of the most common watercolour hues. The clear cover even doubles as a mixing palette. Each tray measures 8cm in diameter and has six 2cm watercolour pans.