WARNING! This Board does NOT have an attachment allowing it to be used with SOLO Easel.If you are looking for a board to attach it to SOLO Easel, here it is:
SOLO Easel's PVC Watercolor Board for Half Sheet

Lightweight and durable, it does not absorb water.
Dark gray, almost black, matte surface.
These are the boards that I always work on.

Dimensions: 43 x 61 cm (17 x 24 inches), 6 mm (15/64 inch) thick.

Perfect for comfortable work with half a watercolor sheet – 38 x 56 cm (15 x 22 inches).
PVC offers an excellent balance of strength and weight and is typically resistant to acids, alkalis, and most other inorganic chemicals.

Weight: 830 g (1.83 lb.)
 
Also please check the Bag for PVC Foam Watercolor Board for Half-Sheet