DLDZ-SD301 Digital Circuit Comprehensive Experiment Box Digital circuit experiment box is the basic experiment teaching instrument of "digital circuits", "pulse circuit" and curriculum designing. It is also one of the basic equipment which develop production and science and technology research and development.Is an ideal teaching equipment in the higher colleges, the professional technical institute, the technical secondary school. Digital circuit experiment box is the basic experiment teaching instrument of “digital circuits”, “pulse circuit” and curriculum designing. It is also one of the basic equipment which develop production and science and technology research and development. When this product was designed full considerate the experimental teaching characteristics, elaborate design, product performance is stable and reliable, and experimental flexibility, to cultivate the students' practical ability. Q1：What factors affect the price? A. The quality of components: All the components we use are real industrial components which under EURO standard. B. Technic: we pay much attention on the technics and details. Our products meet the requirement of Germany standard C. Quantity: The price is up to the quantity of each item. Q2: All equipments are designed by Dolang? A. Yes. All our equipments are designed by ourselves. B. The design department including: Electric research design department, Electrical research design department, Mechanical research and design department, Software research design department, Pilot test department and technical documents department. Q3:Does Dolang have after sales service and training service? A. After sale service: All our products have one year maintance from the date of pick up except artificial damage. B. Training: Customer may ask our engineer to training them in their company or come to Dolang for training