
Cybex Platinum
Cybex Platinum Sirona Si i-Size Car Seat - Sepia Black
Keep your little one safe and snug with the Sirona Si rear-facing car seat. Designed for rear-facing travel up to 4.5 years, it offers up to 50% better protection*, a padded energy-absorbing shell, and Linear Side-impact Protection for 25% more side-impact safety**. The crotch pad and magnetic holders make boarding simple for parents and kids alike. The Sirona Si comes with a Base S for a straightforward, ready-to-use setup, offering smooth one-handed 180° rotation for easy side entry. Simply turn the seat towards the car door to make loading and off-boarding easier, while reducing awkward lifts and making every journey more comfortable for both child and parent. What's Included: Cybex Sirona Si i-Size car seat Base S for installation and rotation Integrated XXL UPF50+ sun canopy- included with the Amber Brown Plus colour only Newborn insert and newborn inlay are available separately as accessories for use from birth. Key Features: Rear-Facing Safety: Designed to keep your child rear-facing up to approximately 4.5 years, with rear-facing travel mandatory until at least 15 months. The padded energy-absorbing shell helps distribute impact forces and keeps your child protected Up to 50% Better Protection: Offers up to 50% better protection compared with the same seat in a forward-facing position during a frontal impact, based on the manufacturer's internal testing 25% More Side-Impact Protection: The integrated Linear Side-impact Protection (L.S.P.) system forms part of a three-tier safety system, helping channel impact energy into the seat's energy-absorbing shell and headrest. The L.S.P. folds away for compact storage 360° Rotation: The Base S enables convenient rotation to make getting your child in and out easier. The product description highlights one-handed 180° rotation for side entry Grows with Your Child: Designed to adapt as your child grows, with an adjustable headrest, M-positioning and a 40% greater recline range in both rear-facing and more upright forward-facing seating positions, as described in the manufacturer's materials Three-Stage Inlay System: Removable inlays help provide a secure, supportive fit from 3 months through early childhood. The comfort inlay offers additional cushioning as your child grows Magnetic Belt Holders: Keep harness buckle tongues neatly tucked to the sides of the seat while you place your child in or remove them, making everyday use simpler Optimal Breathability: All-round air ventilation helps keep your child cool and dry throughout the year. Innovative 3D mesh-style fabric boosts airflow by up to 6× compared with conventional materials, while moisture-resistant fabric and ventilated hard parts enhance comfort Integrated Sun Protection: The XXL integrated sun canopy with UPF50+ protection helps shield your child from sunlight, reduce glare and support more comfortable naps. Its breathable construction promotes airflow, and clever clips allow the canopy to be detached when needed. Soft on Skin: Materials are screened for harmful substances, including heavy metals, phthalates, flame retardants and other restricted chemicals. The manufacturer states that its internal laboratory testing exceeds the applicable regulatory testing standards in the markets it serves Premium Styling: The Plus version features chic two-tone leather-look accents combined with breathable mesh, inspired by luxury car interiors Specifications: Brand: Cybex Model: Sirona Si i-Size Product type: i-Size child car seat Safety standard: UN R129/04 Suitable child height: 61–105 cm; from 40 cm when used with the newborn inlay Maximum child weight: 20 kg Suitable age: Approximately 3 months to 4.5 years; from birth with the newborn inlay as an accessory Rear-facing use: Designed for extended rear-facing travel up to approximately 4.5 years Rotation: Base S rotation system; 180° side-entry rotation referenced in the product description and 360° rotation stated in the key features Installation base: Base S included Headrest: Adjustable Side-impact protection: Integrated Linear Side-impact Protection (L.S.P.) Sun canopy: Integrated XXL canopy with UPF50+ protection Product dimensions: Length 56 × width 45 × height 55 cm Product weight: 7.3 kg Packaging dimensions: Length 73.7 × width 47.5 × height 52.1 cm Gross packaged weight: 15.8 kg Net packaged weight: 12.6 kg
Compare Prices
| Retailer | Price | Availability | Updated | |
|---|---|---|---|---|
| Bundle Baby | £339.95 | Out of stock | 17/10/2026 | Buy now |
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Price History
We started tracking this price on 14 October 2026 — history will appear here as it changes.