Are you looking for professional electricity experiment variable resistance box? If yes, look no further! Our professional electricity experiment variable resistance box must meet your needs. It is one of the best choices for you. Features -Color:Black.-Material: Plastic.-Size: About14.00X10.00X5.00cm/5.50X3.93X1.97in.- It is made of plastic material, durable and safe, excellent and simple, serving for long time.-The variable resistance box is simple and easy to use, bring much convenience to you.-This product is suitable for electrical measurement and other experiments in schools and scientific research institutions.-It is lightweight, easy and convenient to carry and store when not in use without any effort.-The simple design will ensure its high performance as excellent electricity experiment instrument.Packing list: 1 x Variable Resistance Box