Place the unit so the buttons are facing up and the diagonal microphones are facing away from you. Those are the built-in XY microphones.
Top
On the top of the unit near the back is the LCD display. Below this in the center is a horizontal rectangular mixer button.
Below this is the large, round Record button. There is a dot in the center of the button. There are four buttons near the record button. On the top left of the Record button is Stop, with Play on the top right. Rewind is on the bottom left while Fast Forward is on the bottom right.
Below this is a row of three more horizontal rectangular buttons. These are three track buttons which turn on and off Input 1, the internal mic, and Input 2. There are LED status lights above these buttons.
Facing you are the two XLR/TRS combo jacks for Input 1 and 2.
labeled 1, MIC, and 2, with their respective status LEDs above them.
Left Side
The left side of the unit has the Micro SD memory card slot near the front. The tab to open the door faces away from you, with the door hinge on the side closer to you. The card is inserted horizontally with the small ridge on the upper left edge.
About halfway up the left side is a recessed area with the rotary VOLUME dial. Turning it away from you will raise the volume.
Behind the recessed area is a 3.5mm headset/LINE OUT jack for connecting headphones or outputting line-level audio.
Near the back, there's a 3.5mm MIC/LINE IN jack for connecting an external microphone or line-level device. This jack also supports plug-in power for microphones that require it.
Right Side
About halfway up the right side is a recessed area. This has the rotary selection dial set above a horizontal rectangular Enter button.
Behind the recessed area near the top is a horizontal, rectangular USB Type-C port for connecting to a computer, smartphone, or tablet. This port supports USB bus power and can be used for file transfer and audio interface functions.
Below this port is a rubber piece which covers a REMOTE connector for attaching a wireless adapter, such as the ZOOM BTA-1. This allows for wireless control of the H4essential using the H4essential Control app on a smartphone or tablet.
At the back, you'll find the spring-loaded POWER/HOLD switch. Slide this switch towards the front of the device to power the unit on or off. Moving it back until you feel a click turns on the hold function, which locks all buttons to prevent accidental presses during recording.
Bottom
The battery compartment is near the front with the tab facing you. Near the center, there is a raised circle for attaching a tripod or other mounting accessories.