1. Introducción
This manual provides essential information for the correct installation, use, and maintenance of your Cybex ATON S2 i-Size infant car seat. Please read all instructions carefully before using the product and keep this manual for future reference. Failure to follow these instructions may result in serious injury to your child.
2. Información de seguridad
La seguridad de su hijo es primordial. Siga siempre las siguientes pautas de seguridad:
- Nunca deje a su hijo desatendido en el asiento del automóvil.
- Ensure the car seat is correctly installed and secured in the vehicle before every journey.
- The harness system must be adjusted snugly to your child's body, with no slack.
- No utilice la silla de auto si ha sufrido un accidente, incluso si no presenta daños visibles. Los daños internos podrían comprometer su seguridad.
- Always position the carrying handle in the upright position when driving, unless otherwise specified for a specific vehicle installation.
- Do not modify the car seat in any way. Use only original Cybex accessories and spare parts.
- Protect the car seat from direct sunlight when not in use to prevent components from overheating, which could burn your child.
- Refer to your vehicle's owner's manual for specific information regarding child restraint installation.
3. Componentes sobreview
Familiarize yourself with the main components of your ATON S2 i-Size infant car seat:
- Asa de transporte
- Toldo para el sol
- Headrest and Harness Adjustment Lever
- Shoulder Straps and Buckle
- Botón de liberación del arnés
- L.S.P. System (Linear Side-impact Protection)
- Recline Adjustment Lever (if applicable)
- Base Attachment Points (for ISOFIX base)

Figura 1: Lado view of the Cybex ATON S2 i-Size infant car seat, showing its general shape and carrying handle in a lowered position.
4. Configuración e instalación
4.1. Ajuste del asa de transporte
The carrying handle has multiple positions. To adjust, press the buttons on both sides of the handle simultaneously and move it to the desired position. Ensure it clicks securely into place.

Figure 2: The Cybex ATON S2 i-Size infant car seat with its carrying handle in the upright position, suitable for transport.
4.2. Installing with an ISOFIX Base (Sold Separately)
The ATON S2 i-Size is designed for use with a compatible ISOFIX base for secure and easy installation. Follow these steps:
- Place the ISOFIX base on the vehicle seat.
- Extend the ISOFIX connectors from the base and push them into the ISOFIX anchorage points in your vehicle until they click into place. Indicators on the base will turn green.
- Adjust the load leg to the vehicle floor. Ensure it is firmly planted and the indicator turns green.
- Place the ATON S2 i-Size car seat onto the ISOFIX base. Push down firmly until it clicks into place. Check the indicator on the base to confirm correct attachment.
- Pull the car seat upwards to ensure it is securely attached to the base.

Figura 3: Lado view of the Cybex ATON S2 i-Size car seat correctly installed on an ISOFIX base, showing the extended load leg.

Figura 4: Ángulo frontal view of the Cybex ATON S2 i-Size car seat securely attached to an ISOFIX base, ready for use.
4.3. Sistema de protección lineal contra impactos laterales (Sistema LSP)
The L.S.P. System is located on the side of the car seat closest to the vehicle door. Extend the L.S.P. protector by pressing the button and pulling it outwards. This system absorbs impact forces in the event of a side collision.

Figura 5: Posterior view of the Cybex ATON S2 i-Size, illustrating the L.S.P. system extended from the side of the car seat, indicated by the arrow and sound wave graphic.
5. Instrucciones de funcionamiento
5.1. Ajuste del reposacabezas y del arnés
The headrest and harness system are integrated and adjust simultaneously. To adjust, pull the adjustment lever located at the back of the headrest upwards and move the headrest to the correct height. The shoulder straps should be level with or slightly below your child's shoulders.

Figura 6: Interior view of the Cybex ATON S2 i-Size, showing the integrated headrest and harness system with an arrow indicating vertical adjustment.
5.2. Asegurar a su hijo
- Press the red button on the buckle to open the harness.
- Coloque a su hijo en el asiento del automóvil.
- Junte las dos lengüetas de la hebilla e insértelas en la hebilla hasta que hagan clic.
- Pull the adjustment strap at the front of the car seat to tighten the harness until it is snug against your child's body. Ensure you can only fit one finger between the harness and your child's collarbone.
5.3. Ajuste del parasol
The integrated sun canopy can be adjusted independently. Simply pull it forward or push it back to provide shade for your child. It offers UPF50+ sun protection.

Figura 7: Lado view of the Cybex ATON S2 i-Size, demonstrating the adjustable sun canopy in various positions, indicated by the curved arrow.
5.4. Recline Function (Lie-Flat Position)
The ATON S2 i-Size features a recline function that allows for a near lie-flat position, promoting healthy development for newborns. To adjust, locate the recline lever (if present on your model) and follow the instructions for your specific base or car seat configuration.

Figura 8: Lado view of the Cybex ATON S2 i-Size, illustrating the lie-flat position with a graphic representation of an infant lying comfortably.
5.5. Compatibilidad del sistema de viaje
The ATON S2 i-Size can be attached to compatible Cybex strollers to form a practical travel system. Consult your stroller's manual for specific attachment instructions.

Figure 9: The Cybex ATON S2 i-Size infant car seat mounted on a compatible Cybex stroller frame, demonstrating its travel system functionality.
6. Mantenimiento
6.1. Limpieza de las fundas de tela
The fabric covers can be removed for cleaning. Refer to the care label sewn into the fabric for specific washing instructions. Typically, covers can be machine washed on a delicate cycle at 30°C (86°F) using a mild detergent. Do not tumble dry, iron, or dry clean.
6.2. Limpieza de piezas de plástico
Plastic parts can be cleaned with a mild detergent and warm water. Do not use harsh cleaning agents or abrasive materials, as these can damage the plastic.
7. Solución de problemas
- Arnés demasiado suelto: Ensure the harness adjustment strap is pulled firmly and the shoulder straps are at the correct height.
- Car seat not secure on base: Check that all ISOFIX indicators are green and the load leg is firmly extended. Re-install if necessary.
- La hebilla no hace clic: Ensure both buckle tongues are fully inserted into the buckle. Check for any obstructions.
- Difficulty adjusting headrest: Ensure the adjustment lever is fully engaged while moving the headrest.
If you encounter issues not covered here, please contact Cybex customer support or your retailer.
8. Especificaciones
| Característica | Especificación |
|---|---|
| Número de modelo | 521003523 |
| Dimensiones del producto | 66 x 44 x 39 cm |
| Peso del producto | 4.2 kilogramos |
| Peso máximo recomendado | 13 kilogramos |
| Pilas necesarias | No |
| Fabricante | Cibex |
9. Garantía y soporte
Your Cybex ATON S2 i-Size infant car seat comes with a manufacturer's warranty. Please refer to the warranty card included with your product or visit the official Cybex website for detailed warranty terms and conditions. For technical support, spare parts, or service inquiries, please contact your local Cybex retailer or Cybex customer service.