Adjustable size - You can adjust one size up or down. The rings are made from brass and sterling silver plated with a matte, antique oxidized finish. All listed products are handmade, hypoallergenic and have a high resistance to oxidation. Avoid excessive humidity and contact with alcohol and chemicals. Wipe clean with a damp cloth. Try to bend/adjust the ring gently. Bending and twisting the ring too often may cause the material to become weak and eventually lead to break.