Magicshine Seemee 400 ANT+ Smart Rear Light - 360° Visible, 100% Ready

Looking for an upgrade in visibility and control? SEEMEE 400 takes everything great about the SEEMEE 300—and turns it up a notch. With higher output, expanded visibility, smarter syncing, and deeper integration, it’s built for road cyclists and urban riders who expect more from their taillight.

360° Visibility, Trusted by Pros

Both SEEMEE 300 and SEEMEE 400 feature Magicshine’s signature OptiTracing light, projecting a 360° glowing halo onto the road for all-around visibility—a favorite among pro cyclists for its unmistakable presence in low light condition. The Optillumin lens remains the same across both models, offering powerful rear and side illumination through a compact, clean design.

Instant Boosting Alert

Both SEEMEE 300 and 400 feature brake detection—but SEEMEE 400 pushes it further with an instant 400-lumen burst triggered by an upgraded motion sensor. It reacts faster and brighter, giving traffic behind more time to respond and enhancing safety at every brake.

Next-Level Connectivity and Control

As Magicshine’s flagship taillight, SEEMEE 400 brings unmatched integration and coordination to your ride. PelotonSync Flash lets multiple lights flash in unison—automatically syncing with nearby compatible Magicshine taillights. Your group appears as a unified presence, boosting visibility and cohesion on the road.

FTR LightSync Control links seamlessly to the MJ-6558 remote for front-rear control at the push of a button. Prefer cockpit integration? The SEEMEE 400 connects directly with Garmin, Wahoo, and Hammerhead bike computers via ANT+—giving you effortless control right from your handlebars.

Built for Every Ride

SEEMEE 400 delivers up to 107 hours of runtime, USB-C fast charging, and a lockout function to prevent accidental activation. Its IPX6 waterproof rating ensures all-weather reliability, while the quarter-turn mount offers quick, secure installation on seatposts or saddle rails.

SEEMEE 400 is not just a brighter version of SEEMEE 300—it’s a smarter, safer, and more connected evolution. For riders who go farther and ride smarter, it’s the taillight that keeps pace.

Features:

• Dual high-power LEDs output up to 400 lumens for strong road presence and added safety
• Optillumin lens ensures a well-balanced beam with extended side reach
• Signature OptiTracing light projects a 360° glowing halo for all-around safety
• 5 modes: Low, High, Night Flash, Day Flash, and Eco Flash — take your pick
• Smart brake sensor triggers a full 400-lumen alert for added stopping safety
• Auto sleep after 5 minutes of inactivity, wakes instantly with vibration
• FTR LightSync enables remote sync between front and tail lights for streamlined use
• ANT+ integration enables direct control via Garmin, Wahoo, and Hammerhead computers
• PelotonSync Flash syncs with nearby taillights for coordinated group visibility
• Lockout function prevents accidental activation during transport or storage
• Built with a lightweight aluminum housing for lasting durability and a polished look
• Powered by a 1600mAh battery, delivering up to 107 hours of runtime
• Quick quarter-turn mount fits securely on seatposts or saddle rails
• Mode memory function, easy-to-read indicators and USB-C rechargeable
• IPX6 waterproof rating, built to withstand harsh weather
• Warranty: 1 year

Compatible Bike Computers
Garmin, Wahoo, Hammerhead, and other devices supporting ANT+ and the ANT+ bike light protocol.

Operation Instructions:

On/Off - Press and hold the button for 1 second to turn the taillight on/off.

Change Mode - When the taillight is on, single click the button to cycle through Low→High→Night Flash→Day Flash→Eco Flash→ Low...

Memory Function - When the taillight is turned on again, it will automatically turn to the last selected lighting mode.

Low Power Mode - When the remaining battery power is below 10%, the taillight will automatically switch to Eco mode and disable both the vibration wake-up and brake warning functions.

Vibration Wake-Up Function:

• When the taillight is on, single-click and hold the button for 3 seconds to enable or disable the vibration wake-up function. The light indicator will stay solid blue for 3 seconds when enabled, and flash blue for 3 seconds when disabled.
• When the vibration wake-up function is enabled, the taillight enters sleep mode after 5 minutes of inactivity and automatically reactivates upon detecting vibration. If no activity is detected for 2 hours, the taillight will power off completely.

Brake Warning Function - When the vibration wake-up function is enabled, the brake warning function is also activated. Upon detecting braking, the taillight will light up at full output.

Transport Mode - When the taillight is off, press and hold the button for 3 seconds to enter or exit Transport Mode. The light indicator will flash red when entering, and switch from flashing red to showing the battery level when exiting.

FTR LightSync Control Function:

Pair with a Front & Tail Light: Turn on the front and tail lights, press and hold the "○" and "□" buttons on the remote for about 5 seconds until the indicator flashes blue to enter pairing mode. Then, hold the remote close to the front and tail lights until the indicators on the remote and the two light units are constantly blue for 2 seconds, confirming a successful pairing. Once paired, both lights can be turned on and off simultaneously via the remote.

* The front and tail lights to be paired should support the FTR LightSync Control function, and the remote control cannot be paired separately with a tail light.

Pair with a Bike Computer:

• Turn on the SEEMEE 400.
• Turn on your bike computer, go to Menu>Sensors>Add Sensors> Taillight>Search All.
• Select SEEMEE 400 (random number), and click "Add".
• When pairing successfully, the sensor indicates that "Light" is connected.
• Place your bike computer and taillight within 3 meters. Keep 10 meters away from other ANT+ sensors when pairing.

Clear Pairing - When the light is off, single-click the button and hold it for 3 seconds. The indicator will stay solid blue for 3 seconds to confirm successful unpairing. (* ANT+ and FTR can’t be used at the same time. To switch between them, please clear the current pairing first.)

Peloton Sync Flash Mode - Taillights with PelotonSync Flash will auto-sync in a unified flash pattern when set to the same mode and within range.

Charging Indicator:

• Charging: Flashing red
• Fully charged: Constant green for 3 minutes

Battery Indicator - When the light is off, click the button to display the remaining battery level for 3 seconds. GREEN: 100%-21%, RED: 20%-11%, FLASHING RED: 10%-1%