It has a 2.5-slot design and has a beefy cooler with three fans that should do a better job at taming the Vega chip than the stock cooler. These models also feature a nice backplate and come with an additional DVI-I port.
You can expect the Radeon RX Vega 56 and 64 STRIX models sometime in September. The exact specifications (and the pricing) of both cards remains a mystery.
ROG Strix RX VEGA56 OC edition 8GB with Aura Sync RGB for best VR & 4K gaming:
MaxContact Technology that is 2X more contact with GPU for improved thermal transfer. Patented Wing-Blade IP5X-Certified Fans for maximum airflow and longer fan lifespan. ASUS FanConnect II equips with hybrid controlled fan headers for optimal system cooling. Industry Only Auto-Extreme Technology with Super Alloy Power II delivers premium quality and best reliability. ASUS Aura Sync RGB LED synchronization enables a gaming system personalization. VR-friendly HDMI ports let you enjoy VR experiences anytime without having to swap cables. GPU Tweak II with XSplit Gamecaster provides intuitive performance tweaking and real-time streaming.