D'Addario PW-HPK-01

The D'Addario Humidipak Maintain is an automatic two-way humidity control system that keeps the interior of your instrument case at the optimal 45–50% relative humidity without manual adjustments, adding or removing moisture as needed to protect your guitar from seasonal environmental changes. Packets last 2–6 months when the case is kept sealed; for dry instruments, D'Addario recommends using the Humidipak Restore system first.