Galaxy S21 Ultra 128GB 5G (Unlocked) Phantom Black Excellent Condition

The Samsung Galaxy S21 Ultra, launched in January 2021, is one of Samsung’s most powerful flagship phones that still holds strong in 2025. It comes with a big 6.8-inch Dynamic AMOLED 2X display with 120Hz refresh rate and HDR10+ support, giving users smooth visuals and vibrant colors. The phone is powered by the Snapdragon 888 in the USA/China and the Exynos 2100 internationally, both offering excellent performance for gaming, multitasking, and daily use.

One of its biggest highlights is the 108MP quad camera system with 8K video recording, 10x optical zoom, and an impressive 40MP front camera, making it a great choice for photography lovers. The device also packs a 5000mAh battery with fast charging, wireless charging, and reverse wireless charging, so you can stay powered all day. Along with 5G connectivity, IP68 water resistance, and even S-Pen support, the Galaxy S21 Ultra is still considered a premium flagship smartphone that combines style, durability, and top-level features.

Specifications

• Display: 6.8” Dynamic AMOLED 2X, 120Hz refresh, HDR10+, Gorilla Glass Victus
• Performance: Exynos 2100 (International) / Snapdragon 888 (USA, China) with powerful Octa-core CPU + Mali-G78 MP14 / Adreno 660 GPU
• Cameras: Quad rear (108MP + 10MP periscope 10x zoom + 10MP telephoto 3x zoom + 12MP ultrawide) & 40MP front camera, 8K video recording
• Battery: 5000mAh with 25W fast charging, 15W wireless charging, 4.5W reverse charging
• Memory & Storage: Up to 16GB RAM, 128GB/256GB/512GB UFS 3.0 storage (no card slot)
• Connectivity: 5G, Wi-Fi 6e, Bluetooth 5.2, NFC, USB Type-C 3.2, Dual SIM (Nano-SIM + eSIM)
• Design & Build: Gorilla Glass Victus (front & back), aluminum frame, IP68 water/dust resistance, S-Pen support
• Audio: Stereo speakers tuned by AKG, Hi-Res 32-bit/384kHz audio (no 3.5mm jack)

Color Variants

• Black 
• Silver

Key Feature and Benefits of Galaxy S21 Ultra 

Network & Connectivity

The Samsung Galaxy S21 Ultra ensures seamless connectivity with support for GSM, CDMA, HSPA, LTE, and 5G networks. Thanks to its dual SIM (Nano-SIM and eSIM) option, users can enjoy flexibility when traveling across regions with full support for global 5G bands. It also includes the latest Wi-Fi 6e, Bluetooth 5.2, NFC, and GPS for reliable wireless communication. With USB Type-C 3.2, Samsung DeX, and Samsung Pay, the device is built to meet both professional and daily needs.

Body & Design

The S21 Ultra stands out with a premium design, measuring 165.1 x 75.6 x 8.9 mm and weighing around 227g. It features a durable Gorilla Glass Victus front and back, combined with an aluminum frame, giving it a premium and sturdy build. The phone is also rated IP68 for dust and water resistance, protecting it up to 1.5 meters for 30 minutes. For added productivity, it offers S-Pen (stylus) support, making it ideal for business and creative users.

Display

A true highlight of the Galaxy S21 Ultra is its 6.8-inch Dynamic AMOLED 2X display with a 120Hz refresh rate and HDR10+ certification. With a peak brightness of 1500 nits, visuals remain clear even under sunlight. The screen delivers a 1440 x 3200 resolution (~515 ppi), ensuring sharp detail and vibrant colors. The Always-On Display and Gorilla Glass Victus protection make it both functional and durable for everyday use.

Performance & Software

Powered by Android 11 with One UI 3.1 (upgradeable to newer versions), the S21 Ultra runs on either the Exynos 2100 (International) or Snapdragon 888 (USA/China) chipset. Both deliver flagship performance with an octa-core CPU and high-end GPUs (Mali-G78 MP14 / Adreno 660), making the phone perfect for gaming, multitasking, and productivity. This combination ensures fast performance with efficient power management.

Memory & Storage

The device is available in multiple storage options: 128GB with 12GB RAM, 256GB with 12GB RAM, 512GB with 12GB RAM, and 512GB with 16GB RAM. With UFS 3.0 technology, users benefit from faster read/write speeds. While it does not support a microSD card slot, the high-capacity variants provide more than enough space for apps, photos, and videos.

Camera System

The quad-camera setup is one of the strongest features of the Galaxy S21 Ultra:

• 108MP wide camera with Laser Autofocus and Optical Image Stabilization (OIS).

• 10MP periscope telephoto lens with 10x optical zoom.

• 10MP telephoto lens with 3x optical zoom.

• 12MP ultrawide sensor with Super Steady video mode.

For video, it supports 8K recording at 24fps, 4K at 60fps, and 1080p at up to 240fps, with HDR10+ and gyro-EIS for smooth and vibrant results. On the front, a 40MP selfie camera captures sharp photos and supports 4K video recording, making it ideal for content creators and video calls.

Audio

The S21 Ultra delivers immersive sound with stereo speakers tuned by AKG, offering Hi-Res 32-bit/384kHz audio. While it does not include a 3.5mm headphone jack, users can enjoy high-quality audio via USB-C headphones or wireless earbuds.

Sensors & Special Features

Equipped with an ultrasonic fingerprint sensor under the display, the device also includes essential sensors such as an accelerometer, gyro, proximity sensor, compass, and barometer. Unique features like Samsung Wireless DeX, Bixby voice assistant, and Ultra Wideband (UWB) support make it a smart choice for both work and personal use.

Battery & Charging

The phone is powered by a large 5000mAh Li-Ion battery, ensuring long-lasting use. It supports 25W fast charging with USB Power Delivery 3.0, along with 15W wireless charging and 4.5W reverse wireless charging allowing you to charge other devices like earbuds on the go.

Why Choose the Samsung Galaxy S21 Ultra?

The Samsung Galaxy S21 Ultra remains one of the most powerful flagship devices, even when purchased as an unlocked or refurbished smartphone. With its 6.8-inch Dynamic AMOLED 2X display, 108MP quad-camera system, and Snapdragon 888/Exynos 2100 chipset, it delivers exceptional performance for photography, gaming, and productivity. The 5000mAh battery ensures all-day power, while features like 5G connectivity, S-Pen support, and Samsung DeX keep it relevant for professionals and everyday users in 2025. Choosing a refurbished Galaxy S21 Ultra unlocked model gives you premium features at a competitive price, making it a smart long-term investment.

Why Buy from Mobello?

✔ Fast & secure UK delivery

✔ Competitive prices on all iPhone models

✔ Official UK warranty & trusted online shopping

✔ Multiple storage options available

FAQs

Does the Galaxy S21 Ultra support 5G worldwide?
Yes, the Samsung Galaxy S21 Ultra supports global 5G bands, ensuring fast connectivity whether you buy it new, refurbished, or unlocked.

How long does the 5000mAh battery last with daily use?
The 5000mAh battery easily lasts a full day with heavy use, including gaming, streaming, and photography. On average, it provides up to 10–12 hours of screen time, depending on usage.

Is the 108MP camera still worth it for photography and video?
Yes, the 108MP quad-camera system continues to deliver professional-quality photos and videos, with 8K video recording, Night Mode, and advanced zoom capabilities, making it ideal for content creators even in 2025.

Does the S21 Ultra support the S-Pen stylus?
Yes, the Galaxy S21 Ultra is the first in the S series to support the S-Pen stylus, offering enhanced productivity features like note-taking, sketching, and precision editing.