For 500ml bags Material: Bag / Nylon, Tube / Polyvinyl chloride, Inflation bulb / Latex-free Pressure indication: Green / 250-300mmHg, Red / 300mmHg or higher One side is nylon mesh, so you can check the remaining amount of the infusion bag. There is no rupture due to over-inflation. The safety valve automatically releases excessive pressure (300mmHg or higher). Easy to operate with one hand. Can maintain the required pressure for a long time. I have been using it for about a year and a half, so there are signs of use and dirt. It was working fine until the end.