Style 1: Air 3 Broad Compatibility: Designed for Pure Air 3, Pure Air 3 Pro, Pure Air 3 Pro+, Pure Air 4, and Pure Air 4 Pro models. User-Friendly Installation: Install it yourself with basic tools or get professional assistance at a local repair shop. Complete DIY Kit: Includes adapter, cables, and all required parts for a straightforward, no-solder installation. App-Enabled Control: App control lets you adjust speed settings, lock your scooter, and activate anti-theft protection. Enhanced Speed: Increase your scooters top speed to over 40 km/h (25 mph) with quick toggling to 20 or 25 km/h speed limits. Style 2: Mi 4 Ultra Compatibility: Designed specifically for Mi 4 Ultra electric scooters for optimal performance. Enhanced Speed Performance: Boosts scooter speed to over 40 km/h (25 mph) with easy switching between speed limits. Smart App Control: App control lets you control settings, lock your scooter, and secure it with an anti-theft password. Easy to Install: No special skills requiredDIY-friendly or easily installed at any repair shop. Complete Kit Included: Comes with an adapter, cables, and all components for a simple, no-solder installation. Style 3: Mi 4 Pro 2nd gen High Compatibility: Perfectly designed for Mi 4 Pro 2nd Gen electric scooters. Effortless Installation: No soldering required! Includes all parts, cables, and a detailed guide. Enhanced Speed: Boost your scooters speed to 40 km/h (25 mph) with this advanced controller. Flexible Speed Modes: Instantly switch between 20, 25, or 40 km/h with the app or manual controls. Smart Control App: Use the app for full control, including password-protected anti-theft locking. Style 4: Mi 4 lite 2nd gen Designed for Mi 4 Lite 2nd Gen: Fully compatible for seamless integration. Complete Kit: Includes adapter, cables, and everything required for hassle-free setup. Boost Your Speed: Reach up to 35km/h (22mph) with this advanced speed regulator. App Control: Adjust settings, lock your scooter, and manage speed limits easily via the app. DIY Installation: No soldering needed! Comes with all components and a step-by-step guide.