To convert milliliters to liters, you can use the conversion ratio that 1 liter equals 1,000 milliliters.
To convert 6,750 milliliters to liters, you divide by 1,000:
\[ \text{Liters} = \frac{6,750 \text{ milliliters}}{1,000} = 6.75 \text{ liters} \]
Therefore, the cylinder holds 6.75 liters.