Blade Rear Tail Light

Round posts from 27.2 mm to 31.6 mm, straight out of the box. That covers most road, gravel and hardtail bikes. The mount itself is a bit fiddly to install and remove, so leave it on the bike and pop the light off to charge.

Blade uses the same quarter-turn interface as Garmin, so any Garmin-compatible mount works. For aero and D-shaped posts, Sheehy Labs 3D-scans and makes quarter-turn mounts for a huge list of specific bikes and posts. That's who we point people to, and we've been working with them on it.

Not out of the box, but because the interface is a standard Garmin quarter-turn, rack mounts from KOM Cycling, Jefe.bike and others bolt right on. Measure the bolt spacing on your rack first. No saddle-rail mount from us yet; the optic wants to sit high and vertical, and most saddle mounts put it low and tilted.

You can, but don't. The optics are tuned for vertical, upright mounting so the light spreads to make you visible from behind and from the side. Sideways it turns into a glare bomb. If a vertical mount won't fit your bike, email us the details and we'll figure something out.

No brake light or accelerometer. We stuck to what we're good at, which is optics and electronics that put functional light exactly where it needs to be. As a daytime running light it's excellent: bright amber side markers like a car, and a rear beam that's visible from a long way off without pointing a hotspot into drivers' eyes.

250 lumens on high, 125 on low, and both are constant, no fading. About 8 hours on full constant output from the 18650 inside, and when it hits the last few percent it drops into Eco Flash for another 4 hours or so, so it never goes dark on you mid-ride. Four modes cycle by click. Hold the button 3 seconds from off to jump straight to Eco Flash. There's a four-segment battery indicator like all our lights.

Not from us yet; it's on the list but we don't have a date. In the meantime any Garmin quarter-turn seatpost mount will work, and Sheehy Labs makes them for most bikes.

Waterproof enough to survive your rear tire spraying road water directly at it, forever. We cover water intrusion under warranty, so we're highly motivated to make sure it survives very wet rides. The USB port itself is sealed; the rubber door keeps grit out, and if yours came loose email us for the updated rear shell.

By us, free, for the life of the light. Not by you in the field. Charge it up and keep it indoors in the off season and you'll likely never need one.

Three years, plus lifetime support from a real person in our shop. Crashed it, lost the mount, ran it over: covered. Two rules. Be kind to the people helping you, and be honest about what happened so we can engineer the failure out. Details on the warranty page.