Qalo stackable silicone rings provide a safe, comfortable, functional and extremely durable alternative to the traditional wedding ring. Rings are meant to be worn stacked in sets of 2 or 3; show your individuality wherever life takes you. Temperature tolerant from -75 DegreeF to 575 DegreeF, and non-conductive and non-porous. Tensile strength: between 5.5-7 lbs. Of force to break. Qalo rings fit true to size; half sizes should size up.