Campbell
Campbell Chain & Fittings VTG 5770615 3/8" Quik-Alloy® Coupling Link, 7300 Lbs
You will notice the alloy steel surface resists corrosion better than standard steel grades.
Campbell Chain & Fittings 5779235 3/8" Quik-Alloy Coupling Link, Grade 100,
What I appreciate is the alloy steel casing that protects the inner workings from dust.