Cheeba the good thing is that it has grooves already in the centre for a flacid penis to sit in. It weighs roughly 240g. So is a good weight to keep things elongated. There are two parts so you can attach it easily. Then keep it in place with a zip tied or similar.
I use a zip tie which hold the two parts together however If I squeeze the weights together then I do not need to cut the zip tie off it slides off and I can reuse it. The great thing is that on the outside there is a groove also for the zip tie to sit in