Du Mont Laboratories, Inc. 304-A & 304-AR Operating & Maintenance Manual (67008865) by Du Mont Laboratories Inc. Sale $22.00 | / SKU 1533:R Printed Manual - $22.00 Download - $22.00 Printed Manual Download Size 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart This item is a recurring or deferred purchase. By continuing, I agree to the cancellation policy and authorize you to charge my payment method at the prices, frequency and dates listed on this page until my order is fulfilled or I cancel, if permitted. Cathode-ray Oscillograph