According to VergeThe two trackball mice TB450 and TB550 have the same ergonomic design as the previous generations, and their trackball is placed under the thumb. Kensington says its new mice are compatible with Windows, Mac OS, and Chrome OS, and communicate with the target device via Bluetooth or a 2.4GHz wireless connection.
The TB450 mouse is equipped with five programmable buttons, and the TB550 model uses seven such buttons. The more expensive TB550 model is equipped with a more advanced scroll button and can be charged with a USB-C port. The TB450 model is powered by a replaceable battery.