Schaefer's eye jaw and double jaw toggles are manufactured from 316 Stainless Steel. These high fatigue fittings are designed for use with corresponding pin sizes of swage or mechanical type marine eyes commonly used on 1x19 stainless wire.
Both toggle designs are designed to rated approximate breaking strengths of 1 x 19 Stainless steel wire. Schaefer's recommendation, as well as that of most 1 x 19 wire manufacturers, is that safe working loads not exceed 33% of wire breaking strength.