Flexible pregnancy belly bars with clear acrylic balls, these bio flex maternity belly button bars are 20mm long, but can be cut down to a shorter length by using a craft knife and then re-threading with a steel or titanium top ball from your existing navel bar. (make sure you leave enough of the bar for the threads on each end if you want to make the bar shorter.) As the whole bar is bio flex and the has acrylic balls, you can usually keep these pregnancy belly bars in for scans etc.