Magicshine SEEMEE 400 Rear Bike Light

OptiTracing red halo

As well as the two LEDs that shine backwards, the Magicshine SEEMEE 400 features a LED that sits on the underside and projects a 360° red circle of light onto the road around your rear wheel. This means motorists can see you from any direction for increased safety, for example at a junction. And with a quick glance down, you can immediately see whether your rear light is still on.

ANT+ and FTR LightSync

Pair the SEEMEE 400 with your cycle computer via ANT+ and it will switch on automatically when you start your ride and switch off when you stop. With FTR LightSync, you can control your rear light and a compatible Magicshine front light using a single remote control. This way, you will never forget to switch on your rear light again.

Brake sensor

A built-in motion sensor detects when you are braking and instantly switches to a full 400 lumens, just like a car’s brake light. The same sensor switches the light on as soon as you start cycling. If you are transporting your bike, put it in lock mode so that it doesn’t turn on automatically on the car bike rack. You can find out how to do this in the SEEMEE’s user manual.

Compatible with:

• Round seatposts – use the supplied seatpost mount and rubber strap;
• Saddle rails – use the saddle mount supplied;
• Garmin, Wahoo and Hammerhead cycle computers that support ANT+ light control;
• Other Magicshine rear lights with PelotonSync Flash for synchronised flashing in a group.

Not compatible with:

• Standard Garmin or Wahoo mounts – the SEEMEE 400’s quarter-turn mount is smaller and does not fit into them;
• Aero seatposts with a non-round diameter;
• Rucksacks, bags or clothing – a clip to attach the light to these is not included;
• Hub dynamos – the SEEMEE 400 runs on its own battery and has no dynamo connection;
• Cycle computers without ANT+, such as mobile phones with a cycling app – the light will still work as normal but you will need to operate it using the button on the light itself.

Included as standard:

• Magicshine SEEMEE 400 rear bike light
• Seatpost mount
• Saddle mount for saddle rails
• 2 rubber mounting straps
• USB-C charging cable
• User manual

Not included but still needed or useful:

• USB charger or plug – you can charge the light's battery using any 5V USB charger, such as the one for your phone, or via your laptop.

How to mount the Magicshine SEEMEE 400 rear light to your seatpost in 3 steps:

You can install the SEEMEE 400 yourself in a few minutes, without using tools.

1. Secure the mount: Place the seatpost mount against the back of your bike's seatpost and pull the rubber strap around it until the mount no longer moves.
2. Align the mount: Turn the mount so that the light shines straight backwards and not towards the ground or sky.
3. Attach the light to the mount: Place the light at an angle on the mount and turn it a quarter turn until it is secure.

• Only use Day Flash during the day. If you are cycling in the dark, choose Night Flash or High so that other road users can see you clearly; Day Flash mode is too bright for use in the dark and will dazzle those riding behind you.
• Don’t leave the SEEMEE 400 in the shed completely flat during winter. Top it up after every few rides to make the battery last longer.
• If you are going to transport your bike in a car or on a car bike rack, switch on the lock mode. Otherwise, the vibrations will cause the light to switch on automatically and it will be flat when you are ready to ride.
• The light's IPX6 rating means it can withstand heavy rain and splashes but must not be submerged, so do not place it in a bowl of water to clean it; wiping it off with a damp cloth will suffice.