HD6A Hooks fit onto Adapter Arms (HD4).  Hooks also fit Round Outer Slider (C3) 

See photos for placement on Panel Thing.   Price discounted when you order multiple packs of 6.  

Please contact us if you need the earlier style 1/4-20 diameter hooks.  We will substitute the smaller diameter hooks if you send us a message immediately after you buy the package of hooks on eBay.