We use TC4 titanium alloy for the key ring so it has Permanent High Resilience and Life-time Quality that it never deforms in long-term use, being a perfect keychain accessory.
(TC4 material, also known as Ti-6Al-4V, is a remarkable titanium alloy with exceptional properties. Its high strength-to-weight ratio, corrosion resistance, and biocompatibility have made it indispensable in various industries.)