Applicable age and size (manual measurement ±2cm) : 60# Dimensions before inflation External diameter 52cm/22.47inch internal diameter 18cm/7.08inch After inflation External diameter 45cm/17.71inch internal diameter 20cm/7.87inch, suitable for 3-5 years old children (weight 9-20KG). 70# Dimensions before inflation External diameter 62cm/24.4inch internal diameter 20cm/7.78inch After inflation External diameter 55cm/21.65inch internal diameter 22cm/8.66inch, suitable for 5 to 10 years old children (weight 20-30KG). 80# Dimensions before inflation External diameter 72cm/28.34inch internal diameter 25cm/9.84inch After inflation External diameter 65cm/25.59inch internal diameter 30cm/11.81inch, suitable for 10-16 years old children (weight 30-45KG). 90# Pre-inflatable dimensions Outer diameter 83cm/32.67inch inner diameter 30cm/11.81inch Post-inflatable dimensions Outer diameter 75cm/29.52inch inner diameter 35cm/13.77inch, suitable for children over 16 years old and adults (weight 45-70KG). Major Material:Thickened environmentally friendly PVC material