IFD Century 31 Transponder Installation Manual (IF31-IN-C) by IFD Sale $18.00 | / SKU 1728:R Printed Manual - $18.00 Download - $18.00 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.