Traditional haptic interfaces require physical contact between the haptic device and the user. An elegant and novel solution is to provide contactless tactile stimulation via airborne acoustic radiation pressure. However, the characteristics of contactless tactile displays are not well studied in the literature. In this paper, we study the characteristics of the ultrasonic tactile display as a haptic interface. In particular, we examine the effects of increasing the number of ultrasound transducers on four characteristics, namely the maximum producible force, the workspace, the workspace resolution, and the robustness of the simulation. Three rectangular-shaped 2D array configurations are considered: single-tile (10×10 transducers), two-tiles (10×20 transducers), and four-tiles (20×20 transducers). Results show that the maximum producible force remains almost constant as the number of tiles increases, whereas the elevation at which these maxima are generated increases. The workspace increases along the xy-plane as the number of tiles increase almost linearly, however, the elevation of the workspace remains almost the same. Finally, we found that the robustness of tactile display decreases as the number of tiles increases.