A coupling apparatus to mount a second electronic device to a first electronic device, the coupling apparatus comprising: a first coupling part arranged to be coupled with a first electronic device; a second coupling part arranged to be coupled with a second electronic device; and a connecting part comprising: a first plurality of coupling holes including a first plurality of coupling hole sets formed in one end region, each of the coupling hole sets of the first plurality of coupling hole sets comprising at least one coupling hole, and a second plurality of coupling holes including a second plurality of coupling hole sets formed in an opposite end region of the connecting part, each of the second coupling hole sets comprising at least one coupling hole, wherein the connecting part is arranged to be coupled with the first coupling part using a coupling hole set from the first plurality of coupling hole sets, and coupled with the second coupling part using a coupling hole set from the second plurality of coupling hole sets, such that the first coupling part and the second coupling part are connected through the connecting part, wherein neighboring coupling hole sets of the first plurality of coupling hole sets are spaced apart from each other by a first distance, wherein neighboring coupling hole sets of the second plurality of coupling hole sets are spaced apart from each other by a second distance, wherein the first distance is different to the second distance, and wherein a distance between the first coupling part and the second coupling part is adjustable depending on which coupling hole set of the first plurality of coupling hole sets the first coupling part couples to, and which coupling hole set of the second plurality of coupling hole sets the second coupling part couples to. a first coupling part arranged to be coupled with a first electronic device; a second coupling part arranged to be coupled with a second electronic device; and a connecting part comprising: a first plurality of coupling holes including a first plurality of coupling hole sets formed in one end region, each of the coupling hole sets of the first plurality of coupling hole sets comprising at least one coupling hole, and a second plurality of coupling holes including a second plurality of coupling hole sets formed in an opposite end region of the connecting part, each of the second coupling hole sets comprising at least one coupling hole, a first plurality of coupling holes including a first plurality of coupling hole sets formed in one end region, each of the coupling hole sets of the first plurality of coupling hole sets comprising at least one coupling hole, and a second plurality of coupling holes including a second plurality of coupling hole sets formed in an opposite end region of the connecting part, each of the second coupling hole sets comprising at least one coupling hole, wherein the connecting part is arranged to be coupled with the first coupling part using a coupling hole set from the first plurality of coupling hole sets, and coupled with the second coupling part using a coupling hole set from the second plurality of coupling hole sets, such that the first coupling part and the second coupling part are connected through the connecting part, wherein neighboring coupling hole sets of the first plurality of coupling hole sets are spaced apart from each other by a first distance, wherein neighboring coupling hole sets of the second plurality of coupling hole sets are spaced apart from each other by a second distance, wherein the first distance is different to the second distance, and wherein a distance between the first coupling part and the second coupling part is adjustable depending on which coupling hole set of the first plurality of coupling hole sets the first coupling part couples to, and which coupling hole set of the second plurality of coupling hole sets the second coupling part couples to.