These come in variations starting from 50 Ohms, 100 ohms, 500 Ohms to 1000 Ohms.
Electronic Resistance box are designed for accuracy and reliability of results in general physics laboratory experiments.

Physics School Lab Equipment Suppliers in India 

Ltekonline are the manufacturers of Resistance Box Electronic Type Electronic and Electric Lab used to demonstrate engineering principles in Engineering Colleges, Engineering Schools and Physics Lab Experiments for Engineering Teaching Lab in Universities