An outdoor LED clock you don't have to put under a tent.

Solid walnut case, dovetailed at the corners, sealed glass face, threaded stainless mounting points. Every gasket is service- accessible without opening the LED matrix. We run jClocks at marathons in April rain and at outdoor track meets in dust and pollen without covering them.

The IP54 rating means the clock is protected against dust ingress and against water splashes from any direction. For hurricane-edge events or sustained driving rain you can run under a small canopy, but a normal race day in light to moderate rain needs no extra protection.

The LED matrix runs at 3,200 cd/m² — bright enough to read across a finish chute at noon, with the anti-glare panel cutting the bloom that washes out cheaper outdoor LED displays. Adaptive brightness keeps the clock from becoming a spotlight at dusk or invisible at noon.

Eight-inch red LED digits at 638 nm wavelength are visible from up to 80 m in normal lighting and farther at night. Viewing angle is ±60° in both axes, which means the same clock is legible to spectators on both sides of a chute.

jClock uses a LiFePO₄ battery chemistry chosen specifically for cold-weather discharge stability and thermal headroom in summer events. Most lithium-ion-based outdoor clocks lose significant runtime below freezing; jClock holds rated runtime down to −10 °C and back up to 50 °C.

The LED driver is thermally derated automatically — if the ambient gets unusually hot, brightness will trim by a few percent to protect the LEDs without changing the visual output meaningfully. You will not notice; the firmware does its job.