Lenovo's thin T420s laptop weighs less than four pounds, while the T420 gets up to 15 hours of battery life with a standard six-cell battery, and up to 30 hours using an optional nine-cell battery.
Lenovo Unveils Sandy Bridge ThinkPads
Lenovo ThinkPad L420 and L520
Lenovo ThinkPad L420 Laptop
Lenovo ThinkPad T420s Laptop