Rotate object in Unity

RotateObjectBehaviour.cs

using UnityEngine;
using System;

public class RotateObjectBehaviour : MonoBehaviour {
	private float sensitivity = 3f;

	private void OnMouseDrag() {
		float rotX = Input.GetAxis ("Mouse X") * sensitivity * Mathf.Deg2Rad;
		float rotY = Input.GetAxis ("Mouse Y") * sensitivity * Mathf.Deg2Rad;

		transform.RotateAround (transform.up, -rotX);
		transform.RotateAround (Vector3.right, rotY);
	}
}