Water resistant construction. 200 memory channels (20Ch x 10 banks) with 6 character names. Dedicated 121.5MHz emergency key. Side tone function allows you to hear your own voice via an external aviation headset. Optional Ni-Cd, Ni-MH and Li-Ion battery packs. NOAA marine weather channels. Tag scanning and memory bank scanning. ANL (Auto Noise Limiter) for noise reduction.