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 a Quarter Sheet

Watercolor PVC Board.
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 31 cm (17 x 12 in.), 6mm (15/64 in.) thick.
Perfect for comfortable work with half a watercolor sheet.
PVC offers an excellent balance of strength and weight and is typically resistant to acids, alkalis, and most other inorganic chemicals
Weight: 420 g (0.93 lb)
 
Please also check the Bag for PVC Foam Watercolor Board for Quarter-Sheet