See the specifications for the Hydrometer below: 

Application: A measuring device track the fermentation's progress and determine the finished products alcohol content by comparing readings before and after fermentation.

• Features:
  • Accurate
  • Glass materials
  • Alcohol / Specific Gravity / Sugar
• Materials
  • Glass
  • Plant-based Wax
  • Stainless steel bead - S390
  • Paper scale
• Size:
  • Body: Φ17mm
  • Stem: Φ7mm
  • Length: 250 +/-10mm
• Performance Specifications:
• Measuring range: 0.800-1.150 / 0-16% / 26-341
• Accuracy: +/-1 division

Please note, there are no poisonous contents within the Hydrometer.