I rebuilt my deck with composite boards, and used these fasteners, and they worked very well. They are sold by and compatible with TimberTech products, but I'm told they work with other vendors' boards as well. I have two extra boxes of these, unopened. Each box works with approximately 100sf of decking. TimberTech's web site for this product is here: http://www.timbertech.com/product/concealoc/
I paid $175 each for these, and will sell at $150 each.