Qhmpl USB hub supports the following signalling rates low-speed rate of 1.5 mbit/s (183 kb/s) as is defined by USB 1.0 full-speed rate of 12 mbit/s (1.43 mb/s) the basic USB data rate defined by USB 1.1 high-speed (USB 2.0) rate of 480 mbit/s (57 mb/s). Qhmpl hub is capable of chaining up to 127 USB devices truly plug and play automatic with all os including windows 98, 2000, ME, XP ,7,8, virtually all OS USB 2.0 and acpi compliant.