This versatile set of 12 translucent plastic geometric solids uses many of the standard dimensions of Pattern Blocks as each piece's base. Removable lids allow children to compare volume using wet or dry material. Includes six prisms (rectangular- square- cube- small triangular- large triangular- hexagonal)- sphere- hemisphere- cylinder- cone- square pyramid- and triangular pyramid. Ages 8 to 17 WARNING: Choking Hazard - Small Parts. Not for Children under 3 yrs.