Chastity device discussions and reviews discussion

Does anyone know how I can get my Steelworxx cage key copied? Preferably in a metal that won’t rust. Currently, my partner wants me to carry the key inside a necklace I wear. However, humidity builds up inside during showers and such, causing the last key stored there to corrode. Ideally, I want a duplicate made from aluminum or stainless steel. Any suggestions on how to get this done?