Here under the description taken directly from the website Ledragomma Ltd:
"Ideal for a wide range of uses, from gymnastics to rehabilitation, fitness to aerobics, dance, sport, therapy.
These balls are made of the exclusive flexton silpower® (patent) material developed by our company and if used in accordance with the requirements contained in the instructions and warnings manual, they slowly deflate in the event of accidental damage caused by small tears or punctures, thus providing a safety factor to the user.
Available in different pearl colours and in the same 4 sizes of the Original Pezzi® Gymnastik Ball STANDARD, these balls offer a pleasant soft and velvety surface.Furthermore, cuts (up to 5 mm.) or small holes , can be repaired with the specially designed "Fixa-Kit".Each ball supplied in box is provided with a complete exercises guidebook in 6 languages."
We’d like to add something else about this tool. You can see new colors (Acid Green, Purple, Pink,Orange) with the addition of the new Light blue, the colors are an element of trend to a historical tool for playing and gymnastics as the gymball.
GET format! Gymball Evo Training® has taken the official ball, precisely the "Original Pezzi"® Gymnastik Ball Maxafe® of Ledragomma,
both for the colors, but also and especially for the safety, strength, adhesion and overall quality of which the ’company has equipped this ball.
Last, but not least, it must be said that the gymball is an invention just "Made in Italy" of this company and only later were born gymball other in the world, maybe similar, but not with these unique characteristics of their kind.
A brief history of gymball can be read precisely in the book GET! Gymball Evo Training® (you can read something from here in italian language... soon the e-book in english on Amazon!).