Cooling agent foe E liquid 10ml?

OK, I completely understand. What you need is a 10-milliliter coolant for DIY e-liquid.
First and foremost, an extremely important point is this: Pure coolant (concentrated solution) must never be used directly or inhaled alone! It must be diluted with the base oil (PG/VG) and flavoring agent in the exact proportion before it can be safely used.
Below, we will provide you with a detailed introduction to all the key information about the 10 ml electronic e-liquid coolant.
I. Common Types of Coolants
The cooling agents available on the market are mainly divided into two types:
WS-23 (The most commonly used and most powerful)
Features: Offers a pure "cooling sensation" with almost no mint flavor. This is one of the most popular and potent cooling agents available at present.
Feeling: It's like taking a big bite of ice, resulting in a strong, cooling sensation deep in the mouth and throat.
Suggested addition ratio: 0.5% - 2% (usually 1% already shows significant effect, and exceeding 2% will be very stimulating).
Koolada (WS-3)
Features: Provides a refreshing sensation, but with a slight hint of mint flavor. The cooling effect is a bit milder than that of WS-23.
Feeling: It's more like drinking a cool minty drink.
Suggested addition ratio: 1% - 3%
Recommendation: For most users who desire a strong icy sensation, the WS-23 is the preferred choice.
II. How to Purchase and Select
When you purchase "10 ml e-cigarette liquid coolant", you will usually receive a diluted coolant solution already prepared with PG (propylene glycol), and the concentration is typically:
10% concentration: This means that 10 milliliters of the solution contain 1 gram (approximately 1 milliliter) of pure WS-23 or Koolada, with the remainder being PG. This is the most common specification, making it convenient for precise calculation during DIY.
There are also powders or crystals with a purity of 100%, but they are extremely difficult for ordinary users to handle and dissolve. Therefore, it is not recommended that individual users purchase them.
Please confirm when purchasing:
Product name: Clearly marked as WS-23 or Koolada (WS-3).
Concentration: Usually 10%.
Capacity: 10 milliliters.

Brand and Source: Select a reputable supplier of DIY e-liquid ingredients.
III. How to Use (DIY E-Liquid Recipe Example)
Suppose you want to make a 30-milliliter bottle of cool fruit-flavored e-liquid.
Your ingredients:
Vape base: PG/VG mixture solution (for example, 70% VG/30% PG)
Flavoring: The fruit-flavored flavoring you prefer (such as mango flavoring)
Coolant: 10% concentration WS-23 solution (10 ml bottle)
A simple formula calculation (objective: to produce 30 milliliters, coolant addition ratio: 1%):
Flavoring: It usually accounts for 10-15% of the total amount. We will use 12%.
30 milliliters * 12% = 3.6 milliliters
Coolant (10% WS-23): The aim is to ensure that the final e-liquid contains 1% cooling effect.
Since your coolant is at a 10% concentration, the amount to be added is: (1% / 10%) * 30 milliliters = 0.3 milliliters
Simple explanation: With a 10% solution, to achieve a final concentration of 1%, only one-tenth of the amount needs to be added.
Vape oil base (PG/VG): Add the base to make up to 30 milliliters.
30 milliliters - 3.6 milliliters (fragrance) - 0.3 milliliters (coolant) = 26.1 milliliters
Production steps:
Prepare a clean 30-milliliter empty bottle.
Use a dropper or syringe to accurately measure 26.1 milliliters of the PG/VG base and add it to the bottle.
Add 3.6 milliliters of mango essence.
Add 0.3 milliliters of the 10% WS-23 coolant solution. (Remember: It's better to add less rather than more! You can try adding 0.2 milliliters first.)
Seal the bottle cap tightly and shake it thoroughly to mix evenly.
**Steeping (aging)**: Let it sit for a period of time (from a few hours to several days) to allow all the components to blend thoroughly. The coolant usually does not require long-term aging.
IV. Important Notes and Warnings
Safety First: Start with the minimum recommended ratio! Excessive coolant can cause the throat to become extremely cold, numb, and uncomfortable.
The following is the accurate and fluent English translation, following natural and idiomatic English expressions:

"Once again, it must be emphasized that the coolant concentrate solution must not be inhaled directly into the e-cigarette."
Wearing gloves: When handling highly concentrated coolant, it is best to wear gloves to prevent direct skin contact.
Store in a cool place: Protect from light and keep sealed.
Understand local laws and regulations: In your area, the purchase and use of DIY electronic cigarette components may be subject to relevant regulations. Please ensure compliance.
Summary:
What you need is a 10-milliliter bottle of WS-23 coolant solution with a concentration of 10%. After purchasing, please add it according to the exact proportion of the DIY e-liquid recipe. It is recommended to start with an addition of 0.5% to 1% and gradually adjust to find the perfect cooling intensity for you.
Hope these details are helpful to you! DIY e-liquid offers a lot of fun, but please be sure to pay attention to safety.