DreambuilderToy Green X-Large Baseplate, Construction Base Plates, 50x50 Studs (15 x 15), STEM, Compatible to All Major Brands (Green) Brictek Green Baseplate, 15.75" x 15.75" 15-3/4" x 15-3/4" baseplate Fully compatible with other leading brands Warning: choking hazard: small parts; not for children under 3 years