Make it simple to dispense your MMS or Citric Acid Activator. This cap fits perfectly on the 4oz MMS bottle. Simply insert a syringe tip into the special adapter hole in the cap, invert the bottle, and draw out exactly the amount of drops you need! This same set up can also be used to dispense oils etc. The sizes vary according to application. Use separate syringes for each product as to prevent cross-contaminate solutions. This lid also fits onto a 5 and 15 ml essential oil bottles. Having the special adaptor lid on a bottle allows someone to draw out 1 to 20 drops of oil at a time.