The Z310a is a small flip phone for the entry-level crowd. Though somewhat thick at 25.4mm (1"), this stylish handset is smooth, and fits nicely in your hand. The soft curved edges make it feel very sleek. I have the black model for this review, though the Z310a is also available in light pink and a bronze color. The phone weighs 91g (3.2oz) and is nicely weighted so that it feels solidly built, and not too light. The phone does not creak when in use, which further attests to its solid construction.
There is a volume rocker on the left side of the Z310a, with the rest of the buttons being found on the keypad. The flip is well built and snaps nicely into place when opening or closing. The keypad of the Z310a is well lit with bright blue lights. The keys are all on a single membrane, and are separated by raised ridges that make it easy to know which button you're pressing. Like most Sony Ericsson models, the Z310a lacks dedicated end/send buttons, instead using a 'back' button and the softkeys when in a phone call. There is also a multi-tasking/shortcut button on the bottom right of the keypad, which I found to be incredibly useful. The d-pad is a silver ring, and users can configure its four directions to be used as shortcuts to most anything on the phone. I found that all of the buttons had great tactile feedback and were a pleasure to use.
The front of the handset features a VGA camera for snapping pictures, although it unfortunately lacks both a built-in flash and a portrait mirror. Below the camera lens is a smooth glossy area that hides the external monochrome 96 x 64 pixel resolution display. Above the display is a line of indicators that are also neatly hidden when not active. These indicators show when you have a new SMS, missed call, or when your phone is charging or in Silent mode. When active, the external display is visible and will show you the time, as well as scrolling information such as caller's name.
When you open the Z310a, you'll find a slightly small 65k color TFT display with 128 x 160 pixel resolution. The smaller pixel count is noticeable in the icons and menus, showing that this is most certainly an entry-level handset. However, I was able to read the display in direct sunlight, and indoors it is also nice and bright. The handset's speaker can be found on its rear, although sadly I found it to sound somewhat muddled. Likewise, the vibrate feature was not nearly as strong as it should be, meaning that I frequently missed calls if I had the phone in my pocket.
The Z310a features Sony Ericsson's Light Effects, which use a ring of lights along the edge of the phone around the keypad. The effects are user-configurable to any of a dizzying array of colors and patterns, and can be assigned to not only general phone notifications, but also to individual callers. I really enjoyed this feature and wish that more handset manufacturers would integrate light notifications in their handsets.