Willi is a little Danish kid who has many adventures.  In this book, he goes to a "svømmehallen" - a community swimming pool.  At the end are 2 short "how to" pages about how to make your own sailboat for the bathtub, like Willi.  Approximately 7.5 x 7.5 inches.  13 pages.  Twenty-three sides include 1 or 2 short sentences.  Very good condition with minor nicks on the covers, and tag residue on the back cover (see picture).