The product is better than most shutter dogs but has many issues that you should be aware of. I found that the S hooks just spin if you put it together with the parts provided. Be prepared to add stainless washers and different numbers or thicknesses because the manufacturer is not consistent. This is kind of inconvenient if you need it to stay put to hold the shutter. The screws provided rust right away (within two weeks of install). Had to replace them with Stainless Steel after I painted the heads black. The dog platform also started to rust within weeks, they are cast iron so I guess that should not be a shock but also had to remove them all and paint with Rustoleum rust stop black. Makes me wonder why they were not coated sufficiently to last more than a few weeks. I have not seen the S hooks rust at all so that is a plus. So if you are willing to do all that work to units that are not cheap, these are for you!