Iridium Extreme 9575 To Go KitIridium Extreme 9575 To Go Kit. Iridium's newest and most robust Handheld Satphone. Absolutely the most duarable and ruggedized of them all and worth the extra $. If you are using the phone regularly in extreme conditions this is the phone for you. All of our To Go Kits add a spare battery and hard case to the standard basic kit. A new force in mobile communications has arrived. It is the first phone to combine location awareness, SOS, and market