JDT clevis sling hooks are designed in such a way that in the case of overload they NOT break brittle, but hook aperture visually opens and lets the load slowly slide down.
The safety-latch must resist the forces > F 1 + F 2 <. Both forces must have min. 300 kgs or 10 % of the WLL of the hook.
JDT-safety latches reach values which are up to four times higher then the minimum requirements.