2 vibration engines, dual vibration There is no tapping hole in appearance,very beautifull PC USB Vibration GamepadModel No:STK-2021 1. Compatible with Windows 98, 2000, ME, XP, NT, Vista OS.2. 8 directional buttons + 12 fire buttons + 2 analog sticks 3. Turbo, Clear and Auto function4. 2 vibration engines, dual vibration 5. There is no tapping hole in appearance,very beautifull