Kids like big things. Big things are exciting.  Building with super-giant-size blocks is the most fun of all! These hefty, solid, durable structures are made with premium furniture-grade baltic birch plywood and solid northern hardwoods, sanded smooth with rounded edges and finished inside and out. 
     Hollow Blocks are based on a unit size of 4" x 4" x 7 3/4" (the "Small Single Square"). Small double square is 8 x 4 x 7.75.