The ZenFone 2 is well-made for the price. It’s an all-plastic device, but there is very little flex or creak. The back is plastic composite with a faux brushed aluminum appearance. Plastic masquerading as other materials can sometimes seem chintzy, but Asus does a good job here; this reviewer was initially fooled into thinking it actually is aluminum. The texture is a bit rough, making it more grippy than smooth glass or metal but not as grippy as the rubberized back of the Moto X.
The design of the rear panel is very linear, with all of the elements stacked in the center. The dual-color LED flash is located towards the top. Just below this is the rear camera, which is surrounded by a raised circular ridge to help protect the lens from getting scratched.
Similar to the LG G4, the elongated volume rocker, with a texture of circular ridges, is located on the back. This arrangement takes a little getting used to, but is less prone to accidental button presses. The volume rocker is fairly clicky yet easy to press, an important distinction considering the user will have to brace the sides of the device against their fingers and thumb in order to change the volume. The rocker switch is not as easy to locate as it is on the G4, however. The ZenFone’s switch is fairly narrow, and it’s difficult to tell if you’re touching the upper or lower half without any tactile indicator at the center.
The Asus logo stands out against the brushed red finish of our review unit, while the Intel and Zenfone logos fade into the background a bit, a nice touch considering all the logos and branding emblazoned on the backs of past devices. Near the bottom edge sits the speaker grille, stretching horizontally nearly the full width of the phone. The length of the grille suggests the use of multiple speakers, however, removal of the back cover reveals only one small mono speaker on the left side. This is a little disappointing considering more recent phones like the Nexus 6, Moto X, and HTC One M9 all have stereo front-facing speakers.
Removing the back cover is a little tricky: A small indentation for inserting a fingernail or tool is situated on the lower-left side but the plastic clips that hold the cover in place are difficult to release. Underneath the cover, the microSD card slot and the two micro-SIM card slots are situated along the centerline. The 3000mAh battery can be spotted beneath the frame that holds the cards in place, however, it is non-removable. Mounted on the inside of the back cover is the black rectangle of the NFC coil.
The power button sits in the middle of the top edge, which makes it rather difficult to reach considering the size of the device, requiring some awkward finger shifting to activate one-handed. Flanking the power button are the 3.5mm headphone jack and noise canceling microphone. The microUSB 2.0 port is centrally located on the bottom edge with a microphone offset to one side. Moving the buttons to the top and back leaves the sides smooth and unmarred.
Flipping the phone over reveals a black expanse dominated by the 5.5-inch HD LCD display covered with Gorilla Glass 3. With a body to screen ratio of 72%, the bezels are thin but not quite as thin as the LG G4. Surrounding the perimeter of the front face is a slightly raised plastic trim, creating a sharp edge that feels uncomfortable when held against the ear and face during phone calls. This seemingly small detail is the one thing about the ZenFone 2’s plastic design that does feel cheap.
Centered above the screen is the earpiece and an Asus logo. To the right is the front-facing 5 MP camera and an RGB LED for notifications. To the left, just barely visible, are the proximity and ambient light sensors.
Below the screen, from left to right, are the standard Android navigation buttons for back, home, and recent apps. Asus decided to go with old-school capacitive buttons as opposed to the more modern onscreen virtual buttons. Unfortunately, the buttons are not backlit—only lined with reflective material. This becomes an issue when trying to operate the phone in a dark environment. You simply have to guess where the buttons are or become familiar enough with their location and layout that you know where to put your fingers. Beneath the sometimes-difficult-to-see row of buttons is a small plastic chin with the same circular-ridged texture as the volume rocker.
Except for the sharp edge around the front, the ZenFone 2 is pretty comfortable to hold. The back curves smoothly against the palm, reminiscent of the Nexus 6, and its all-plastic construction makes it relatively light for its size. The flat sides make gripping the phone a little easier and the rounded corners do not dig into the palm or fingers. However, the brushed finish is a bit on the slippery side so shifting one's grip can be a tricky proposition. The center of balance rests just below the Asus logo on the back so most of the time it does not feel like it’s going to flip out of your hand. As with many devices in phablet territory, it feels awkward to stretch your thumb across the screen or up near the top. Either movement requires shifting your fingers so they no longer press the device securely into your palm and shimmying your thumb into position. Thankfully, Asus includes a one-handed mode similar to Samsung’s implementation on the Note 4, but generally, the ZenFone 2 is best operated with both hands.