|Component|Model 01|Model 01+|Model 02|Model e2|Model 2+ (Pre-production)|model 03 (China Copy)|
|---|---|---|---|---|---|---|
|CPU|Transmeta Crusoe 1 GHz|Transmeta Crusoe 1 GHz|Via C7M ULV 1.6 GHz|Via C7M ULV 1.6 GHz|Intel Atom Z540 1.86 GHz|Intel atom Z550 1.2 GHz dual core|
|RAM|256MB DDR|512MB DDR|1GB DDR2|1GB DDR2|2GB DDR2|2GB DDR2|
|Hard Drive|20GB HDD|30GB HDD|120GB HDD or 64GB SSD|120GB HDD or 64GB SSD|120GB HDD or 64GB SSD|120GB HDD or 64GB SSD|
|Display|5" Transflective 800x480 LCD|5" Transflective 800x480 LCD|5" 800x480 LCD|5" 800x480 LCD|5" active matrix 800x480 OLED|4.8" active matrix 1024X600 OLED|
|USB|1.1|2.0|2.0|2.0|2.0|2.0|
|Wi-Fi|802.11b|802.11b|802.11a/b/g|802.11a/b/g|802.11a/b/g|802.11a/b/g/n|
|WWAN|n/a|n/a|EVDO from Sprint or Verizon|HSDPA|EV-DO and HSPA|HSDPA 3G|
|Bluetooth|1.1|1.1|2.0|2.0|2.0|2.1|
|Wacom|Yes|Yes (Improved accuracy)|Yes|Yes|Yes|unknown|
|GPU|Silicon motion Lynx 3DM+|Silicon motion Lynx 3DM+|VIA VX700|VIA VX700|Intel GMA500|Intel GMA500|
|Removable Battery|4,000 mAh or 8,000 mAh|4,000 mAh or 8,000 mAh|4,500 mAh or 9,000 mAh|4,500 mAh or 9,000 mAh|4,500 mAh or 9,000 mAh|4,500 mAh or 9,000 mAh|
|Battery Type|lithium polymer|Lithium Polymer|lithium ion polymer|lithium ion polymer|lithium ion polymer|unknown|
|Docking Cable|USB 1.1|USB 2.0|replaced by dongle or dock|replaced by dongle or dock|replaced by dongle or dock|replaced by dongle or dock|
|Dock|Zinc stand|Zinc stand|Gloss Black w/ optical drive|Gloss Black w/ optical drive|Gloss Black w/ optical drive|Gloss Black w/ optical drive|
|Ethernet|10BaseT|100BaseT|100BaseT|100BaseT|100BaseT|100BaseT|
|Dongle|||RJ45 & VGA|RJ45 & VGA|unknown|unknown|
|Keyboard|57 key|57 key|58 key|58 key|58 key|58 key|
|Weight|397g|397g|413g*|413g*|413g*|426g*|

Question: how many models use a usb docking cable?
Answer: 2