The shirts are described as kids' tees made of 60% cotton and 40% polyester, a lightweight single-layer novelty fabric with a crew neckline, short sleeves, and a relaxed, cropped fit.
The board book has five buttons that play an instrumental version of "Into the Unknown" and a sixth button that plays the song sung by Elsa. It includes three replaceable AG13 button-cell batteries.
Care notes recommend machine washing (cold, inside out, with similar colors). For drying, the product suggests tumble drying low or line/lay flat to dry; hanging to dry is noted as best for preserving the shirt.
The board book is published in English in a board-book format, and the song lyrics are printed in the book.
Both items feature iconic Frozen characters, including Elsa (the board book also mentions Anna). The shirts specifically display a portrait of Elsa with the text "Into the Unknown" across the front.
The shirts are made to order using digital direct-to-garment printing and are printed in the U.S.A. with water-based inks.