Introduction
This manual provides comprehensive instructions for the safe and effective use of your kmaier S12 Wearable Breast Pump. Please read this manual thoroughly before first use and retain it for future reference.
What's in the Box
- Breast Pump Motor (x2)
- Milk Collector Cup (x2)
- Flange (24mm, x2)
- Valve (x2)
- Linker (x2)
- Diaphragm (x2)
- USB Charging Cable (x2)
- Bra Adjustment Buckle (x2)

Image: The contents of the kmaier S12 Wearable Breast Pump package, including two assembled pumps, two USB charging cables, and two bra adjustment buckles.
Safety Information
- Wash all parts that come into contact with breast milk with warm, soapy water after each use.
- Sterilize all parts regularly, especially for newborns.
- Ensure all components are correctly assembled to prevent leakage and maintain optimal suction.
- The product uses food-grade silicone and is BPA-free.
Product Features
- Hands-Free Design: Allows for pumping at home, in the office, or while traveling, providing freedom of movement. Each pump can hold up to 6 oz (180 ml) of breast milk.
- Multiple Modes & Levels: Features 4 distinct modes (Expression, Massage, Pumping, Auto) and 12 adjustable suction levels to cater to individual comfort and milk flow needs. The maximum suction reaches 285mmHg.
- Low Noise Operation: Operates at less than 40 decibels, ensuring quiet use without disturbing your baby or others.
- Leak-Proof System: Designed with backflow prevention. If leakage occurs, verify correct assembly of all parts.
- Easy Operation: Equipped with 4 intuitive buttons for simple mode switching and suction adjustment.
- Safe & Easy to Clean Materials: Made from food-grade, BPA-free silicone. All accessories are detachable for thorough cleaning.

Image: Visual representation of the four pumping modes and twelve intensity levels available on the kmaier S12 breast pump.

Image: The kmaier S12 breast pump operating quietly, indicated by a graphic comparing its 40dB noise level to other sounds, with a baby sleeping nearby.

Image: Detailed view of the LED display and control buttons on the kmaier S12 breast pump, showing indicators for mode, level, battery, and timing.
Setup and Assembly
- Insert the valve into the linker.
- Attach the diaphragm tightly to the milk collector.
- Align the linker with the "ear" on the milk collector.
- Press the edge of the flange firmly onto the milk collector, ensuring a tight seal.
- Connect the pump motor to the assembled milk collector and flange unit. Ensure it clicks securely into place.

Image: Exploded view of the kmaier S12 breast pump components, labeling the flange, milk collector, pump motor, valve, linker, and diaphragm.

Image: A six-step visual guide demonstrating the correct assembly of the kmaier S12 breast pump, from individual parts to the complete unit.
Flange Sizing
The pump comes with a 24mm flange. Ensure the flange size is appropriate for your nipple to ensure comfort and effective milk expression. Incorrect sizing can lead to discomfort or reduced milk output.

Image: A guide on measuring nipple size for proper flange selection, with illustrations of correct and incorrect flange fits.
Charging
Connect the provided USB cable to the pump motor and a suitable power source. The LED display will indicate charging status. A full charge allows for 2-5 pumping sessions.

Image: The kmaier S12 breast pump motor connected to a power bank for charging via its USB port.
Operating Instructions
- After assembly, place the pump inside your bra, ensuring the flange is centered on your nipple.
- Press the power button to turn on the pump.
- Use the mode selection button (M) to cycle through the 4 modes: Expression, Massage, Pumping, and Auto.
- Adjust suction levels (1-12) using the '+' and '-' buttons to find your comfortable and effective setting.
- The LED display shows the current mode, suction level, and pumping duration.
- The pump features a 30-minute auto shut-off function.

Image: A woman demonstrating the hands-free use of two kmaier S12 wearable breast pumps while engaged in work.
Official Product Video: How to install the wearable breast pump
Video: This video demonstrates the step-by-step process of installing the kmaier S12 wearable breast pump, ensuring proper fit and function.
Collecting Breast Milk
- Once pumping is complete, turn off the pump.
- Carefully remove the pump from your bra, keeping the flange facing upwards to prevent spills.
- Detach the pump motor from the milk collector.
- Pour the collected breast milk from the milk collector into a storage bottle or bag.

Image: A three-step visual guide demonstrating how to safely remove the pump motor and transfer collected breast milk into a storage container.
Cleaning and Maintenance
All parts that come into contact with breast milk should be cleaned after each use and sterilized regularly.
- Disassemble all components: pump motor, milk collector, flange, valve, linker, and diaphragm.
- Wash all non-electrical parts with warm, soapy water. Use a soft brush for thorough cleaning.
- Rinse thoroughly with clean water.
- Sterilize parts as recommended (e.g., boiling, steam sterilizer, or dishwasher safe).
- Allow all parts to air dry completely before reassembling or storing.

Image: A hand demonstrating the flexibility of the food-grade, BPA-free silicone material used in the kmaier S12 breast pump components.
Troubleshooting
- Low Suction: Ensure all pump components (flange, valve, linker, diaphragm, milk collector) are correctly and tightly assembled. A loose connection can significantly reduce suction. Check for any damage to silicone parts.
- Leakage: Verify that the diaphragm is tightly connected to the milk collector and that the flange is securely attached. Improper assembly is a common cause of leakage.
- Pump Not Turning On/Charging: Ensure the USB charging cable is properly connected and the power source is active. If the battery is completely drained, it may take a few minutes for the display to light up.
- Reduced Milk Output: Check flange size for proper fit. Ensure you are using the correct mode and suction level for your body. Stress and hydration can also affect milk output.
Important Note on Assembly
Incorrect assembly is a primary cause of issues like low suction or leakage. Always refer to the assembly instructions and ensure all parts are securely fitted.
Specifications
- Model: S12
- Brand: kmaier
- Material: Food-grade Silicone, BPA Free
- Product Dimensions: 0.5 x 0.5 x 0.5 inches
- Item Weight: 1.3 pounds
- Power Source: USB Cable
- Pump Type: Electric
- Modes: Expression, Massage, Pumping, Auto (4 modes)
- Suction Levels: 12 levels
- Flange Size: 24mm (standard)
- Milk Collector Capacity: 6 oz / 180 ml
- Noise Level: Less than 40 decibels
- Additional Features: Hands-Free Usage, LED Electronic Display, 30-minute Auto Shut-Off
Warranty and Support
For warranty information, technical support, or to order replacement parts, please contact kmaier customer service through the retailer where the product was purchased.