For this model, we want to add some markers to indicate the volume of water contained in the bottle. We want to ensure these level markers are accurate, so we will need to check the volume contained at each level. First, we will add a reference plane to cut the model at our desired level. This can be accessed under features, then Reference geometry or by selecting a plane. In this case, the top plane and holding the control key were left click dragging as a shortcut. We will loosely position the plane and then stop dragging the mouse. We can now enter an offset value of 100mm to start with. We can always come back later to adjust this. The plane can be renamed to fill level. Now that we have a reference plane which is sectioning the model, we can access the intersect tool. To do this, search for the command in the top right search bar. Press the S key to access the shortcut toolbar and search from within that within the intersect tool. We will select the plane and the two separate solid body components for the bottle, the window and the main body. Since they would be molded separately. Choosing the create both option and clicking intersect will result in the command generating a series of intersecting bodies. We are only interested in the body representing the water for now. Select just this region and then select Invert Selection to choose only the volume of liquid to keep. Once we've finished testing, we can come back to include the solid bottle bodies. Now we are left with just the internal volume captured by a reference plane. To find the exact volume of this, go to the evaluate tab and then select Mass Properties. Here we can see that the volume of this region is 725ml. Interested in learning more about Advanced Celebrates commands and workflows? Consider attending one of our certified SOLIDWORKS training courses in-person or online, where you'll learn to model efficiently and make the most out of your software. To finish, we want to add a mark line to represent one liter of liquid volume. Due to our design choices, we can simply go to the feature tree and edit the offset value of our plane until the resulting body volume is one liter. This may take some trial and error, but after a few iterations we reach a suitable value of 134.4mm. We can then use this information to add a decal or emboss to show where the one liter fill line lies. For more information on this example, check out our accompanying blog here. Be sure to keep an eye out on our website and YouTube channel for more SOLIDWORKS content.