SELCAL units designed specifically to ARINC characteristic 531 are only available in limited quantities. Avtech urges new or existing customers to consider migrating to SELCAL units designed per ARINC 714. The ARINC 714 units have improved operational characteristics over the older ARINC 531 units and are less likely to be subject to part obsolescence problems associated with older types. Please note that migrating to the 714 series of SELCAL units will require aircraft modifications.

• The N1335C and the N1401C are designed per ARINC specification 531. The N1335C model is packaged in a 1/4 ATR short case and the N1401C model is packaged in 1/2 short case per ARINC specification 404A.
• Form, fit and functionally interchangeable with original factory equipment