You need ActiveSync 4.0 to synchronize with Microsoft Windows Mobile 5.0-based devices.
You do not need a Windows Mobile 5.0-based device to use ActiveSync 4.0.
Some features require additional hardware.
Some features are not available on all devices. Check with the device manufacturer or the mobile operator for features that are specific to the device.
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.