Wooden Frame with 3 U-Shaped Wires and plastic beads Ideal for childhood education 13" tall, 4" long and 6" wide Great tool for development of early number skills 20 beads per wire. A simple device for counting and basic arithmetic. The Abacus is among the first calculating devices ever used. Consists of a wooden frame with 3-U shaped steel wires. Make developing number skills fun for young students.