Excerpt: When I first got this, it didn't fit over the rubber foot for my 681B pod (the foot is too huge). I tried putting the spike on without the rubber foot and, though it fit, was heart attack inducing to tighten. Even after tightening I could still pull it off with little effort. So I messed around with the bearing on the screw and then the nut. I turned the nut around (so the text is facing outwards) and it became far easier to tighten.
Excerpt: I was originally going to buy a replacement rubber piece, but I couldn't find the one I needed. So I ended up ordering this spiked foot instead. Works really well and makes my monopod rotate smooth on the ground.
Pros: Easy To Use, Fits Well, Improves Tripod Function, Solid/Sturdy
Summary: This spike is much bigger than anticipated, easy to fit to monopod. Footplate helps easy penetration of soft ground and it will then stand up on its own. Matches the Manfrotto monopods for robustness.