No, you do **not need to fill the machine or the cartridges with water** before use. The FacialDefy 4.0 cartridges are ready to install and use. Simply select the correct cartridge, attach it securely, and apply enough conductive ultrasound gel between the cartridge and the skin during treatment. Please do not open the cartridge or attempt to add water yourself. 

If the plastic test sheet is not showing any dots or lines, please check the following: - Apply enough ultrasound gel between the cartridge and the test sheet. - Make sure the cartridge is fully flat against the sheet. - Confirm the machine is in READY/working mode and the energy level is not set too low. - Make sure you are using the correct test sheet thickness for the cartridge depth. If there are still no visible or tactile marks after testing correctly, please stop using the machine and contact **service@freyara.com** with your order number and a short video of the test. Our team can help check whether the cartridge is outputting normally. 

Yes, you can use both RF and the FacialDefy 4.0, but we recommend **not using them on the same facial area at the same time**. For a safer routine, stop RF for about **1 week before HIFU**, and wait around **1–2 weeks after HIFU** before restarting RF, or longer if the skin is still red, tender, or sensitive. Also, HIFU should not be used as frequently as RF. Allow the recommended recovery period between HIFU treatments on the same area.  

Yes. The FacialDefy 4.0 is suitable for body treatments and includes 6mm, 9mm, and 13mm body cartridges. It may help improve the appearance of localized fat and contour areas such as the belly, love handles, and thighs while also supporting skin tightening. Results vary depending on fat thickness, treatment settings, and individual response, so it cannot guarantee a specific amount of fat reduction.  

Yes, replacement cartridges are available for purchase separately. Please choose the cartridge that matches your FacialDefy 4.0 machine and the treatment depth you need, such as 1.5mm, 2.0mm, 3.0mm, 4.5mm, 6.0mm, 9.0mm, or 13.0mm. If you are not sure which cartridge to buy, please email your order number and a photo of your current cartridge to [service@freyara.com](mailto:service@freyara.com). Our team will help confirm the correct replacement before you purchase.  

A hip replacement is considered a metal implant, so we do not recommend using this device without approval from your surgeon or healthcare provider. Do not use HIFU on or near the replaced hip. Even if you only plan to use it on your face, please consult your doctor first to confirm that it is suitable for you.  

For the same treatment area, please wait at least 2 weeks between HIFU and ultrasonic cavitation. When using a separate radiofrequency device, we recommend waiting at least 7 days before or after HIFU, and only treating the area after any redness, tenderness, or sensitivity has completely disappeared. HIFU FacialDefy 4.0 should be used on the same area only once every 3 months.  

Yes, it works with 110V US power. Orders for the United States are supplied with the correct 110V-compatible power cord and US plug, so no voltage converter is needed.  

Yes, it can be used on wrinkled hands to help improve skin firmness and the appearance of fine lines. However, please avoid treating directly over large or protruding veins, as the hand area is quite thin and sensitive. We recommend using a low energy level first and testing on a small area. 

There is a difference. The analysis is more in-depth and comprehensive, yielding better results. For more details, please visit our product page, where you’ll find a section comparing HIFU machines. This will help you better understand the options.