This is an Erg Synapse Necklace. I purchased it 10 years ago and used it a few times, but it has been stored away since then. There is no case. Please consider this item as a used product. * It will be washed and dried before shipping. The effects of the Erg necklace are said to improve body balance, core strength, performance, fatigue reduction, and relieve stiffness through **"super-vibration at the subatomic level."** It is widely supported by top athletes and general users alike. Special processing (Erg processing) is applied to rare natural minerals, and their vibrations resonate with the body like nerve transmission, drawing out the inherent potential and recovery power, making it a "body tune item." Models that are used in conjunction with magnetism can be expected to relieve stiffness by promoting blood circulation in the neck and shoulders. Thank you for viewing.