Here's a look at the mTrix portable MPEG4 video and MP3 audio player from PQI. This device measures 6.84 x 6.8 x 2.57cm (2.69 x 2.68 x 1.01 inches) and weights 110g (0.24lb).
It features a 2-inch 320 x 240 pixels LCD display and supports MP3 (CBR/VBR), WMA and WAV audio along with ASF, AVI and MOV video.
The mTrix has only an amazingly low memory capacity of only 32MB but fortunately you can expand this with with MMC/SD/Intelligent Stick memory cards.
The player has a rechargeable Li-ion battery, (3.7V, 1050mA) and features a battery life of 4 hours for video, 6 hours for audio with LCD off with SD cards and a battery life of 3.5 hours for video, 5.5 hours for audio with LCD off when using I-Sticks. The charging time of the mTrix is 1.5h with adapter and 4.5 hours with USB cable.