Groove of 360PT≈9.1mm，card protector outer size:73mm 110mm 13mm. Magnetic Open and Close: The cases are sturdier then sleeves, penny sleeves, as it features a magnetic open and close design with a hard Acrylic casing to keep the cards safe.
Fits55PT/75PT/100PT/130PT Magnetic card holder. Cards and magnetic card holders (e.g., 35PT or 130PT) are not included. New Portable Guitar Chord Trainer Guitar Chord Presser with 16 Chord Buttons. Fits35PT/55PT Magnetic card holder.