Surrender control to stainless steel with this 4mm sound. For enthusiasts of bondage medical play, there's nothing sexier than stainless steel, and this certainly delivers, with a single 4mm (0.157 inch) dilator from Rouge Garments for medical play. Sanitary and gleaming, this rod will certainly intimidate those who know, and draw a shudder of anticipation from those who want more. Insertable 130 mm.