The Shroom, just like a mushroom has a flared head and a slimmer shaft. Also known as the Headmaster Senior this one measures 8 inches high of which 7 is insertable. The head is a whopping 4inches wide 13 inch diameter, and the shaft is 2? inches wide, which is about 8 inches around. The toy is made with firm PVC and whilst it is fairly firm but flexible. A big favourite already with customers that like the bigger, wider toys.