21 Rod Student Abacus offered by us is made using superior quality thermoplastic polymer with help of molding technology. It is intended to be used for teaching math and helping in solving complex math calculations. This abacus is perfect for both kids & adults and assists in sharpening mind math skills that are very important in clearing competitive exams. It can also be presented to children on any special occasion. 21 Rod Student Abacus is available in different color combinations at reasonable rates for our respected customers.