Acer had the Liquid E3, and they were also showing the Liquid Z4 here at Mobile World Congress. The Z4 takes things down a step as compared to the E3. Basically, if the Liquid E3 were in the mid-range lineup, the Liquid Z4 has arrived to fill the lower end of that space. The handset sports a 4-inch display and is powered by a dual-core 1.3GHz processor.