E-Rigging.com offers Hook x Hook Turnbuckles in Galvanized and Stainless Steel.
Here is the best use cases for the end fittings on this type of turnbuckle:
Turnbuckle Hook End Fittings
Turnbuckle Hook end fittings are perfect for quick connections on temporary rigging applications. The hook is large and durable enough to connect to many other rigging fittings. The hook end fitting type is not recommended for critical or dynamic applications. If the load is removed from the assembly, the hook end fitting may disconnect from the other fittings.