Grover Pro Tunable Tambourine. The Grover Pro Tunable Tambourine affords players who prefer a natural skin head the ability to maintain a consistent head tension regardless of the temperature and humidity. Our titanium tuning pins grant players a tuning Range not previously possible with professional-level tambourines. Our exclusive design produces no extra bulk and negligible extra weight because the tuning mechanism is completely internal. In addition to being tunable, the Grover Pro Tunable Tambourine is customizable: The 18 jingles of the top row are interchangeable, allowing for an unbelievable number of different combinations to customize your sound. Jingle Packs sold separately. NOTE: Do not over-tension the head. Always lower the tension of the head after playing to ensure the head is not damaged if the weather changes!