This little speaker box or amplifier if you will, enhances or increases the sound that is produced from your iPhone when placed inside the slot at the top of the box. It will sound best without a cover on your phone of course. The slot at the top measures approximately 2 7/8 inches wide by about 5/16 inches. My iPhone 8 fits quite nicely in it with a little extra room. But, be sure to check the dimension of your phone to ensure a good fit. Other configurations of this design may be custom ordered to fit your phone requirements no matter what kind of electronic hand held phone you use. The front of the speaker box has a 1 ¼ diameter hole, perfect to enhance the quality of volume coming from your phone. Keep in mind that this amazing speaker box uses NO electronics of any sort to produce increased sound from your device. It relies on purely on science "the science that deals with matter, energy, motion, and force". Simply place your phone in the slot, select your music or audio of preference, turn up the volume on your phone and enjoy. The hardwood has been hand sanded and finished beautifully then sealed with multiple applications of a hard Tung oil finish to ensure a rich look to the wood grain.