The SH has an open ended hook, it works best when loaded onto the strip right at retail. Our other recommendation, especially if you are pre-loading the strips, is the SH , which has a pinched hook and is securely fastened to the strips and will not come off during shipping. Our recommended strip s hooks are all metal s hooks, if unsure what version is right for your needs go online and ask for free samples. If you are confident in your needs, buy s hooks in bulk to enjoy significant quantity discounts or even when purchased at lower quantities, our prices are always affordable. If you require S-Hooks for needs other than for strip hanging.