Based on the original four bar mechanism of walking beam pumping unit, we mount the equalizer on the upwards of walking beam, the rear end of walking beam is bent and adding a barbell at the downwards of walking beam, combined with crank balance to become a compound balance, so the balance effect is better than before, the usage life of reducer is prolonged, the power of electric motor is smaller than before , the waving scope of electric current becomes small, it can save about 30% energy. 1.Wooden box or as per the customer's requirement 2.15-45 working days after receiving the copy of l/c or prepayment