Great question. Yes, these can be used without the posts. A Toggler anchor is included should you decide to not use the post. I must point out the fact that if you are using them for panels or something heavier than a valance, they may not hold up to the weight.
Another point i should make is that you will not have enough projection for a 3.75" return. (The return is the side of the treatment that turns back toward the wall on the end of your treatment.) The long screw will be visible unless you screw it all the way into the wall.
*****Our supplier sent an entire shipment with this long screw by mistake - rather than sending the shorter screw we have manufactured to work with our posts. Instead of returning them, we were given a break in the pricing so we are passing this break on to our customers. To use this knob with our posts, we recommend cutting the screw down some so that it can be screwed into the post all the way. This is easily done using bolt cutters.
We only have a few of these discounted finials left in stock. When they are gone so is the fantastic pricing ! They are regularly $9.00 each.