Sizes to fit a variety of dog breeds
* S: 12 - 16 in / 30.5 - 40.6 cm
* M: 16 - 20 in / 40.6 - 50.8 cm
* L: 20 - 24 in / 50.8 - 61 cm
* XL: 24 - 28 in / 61 - 71 cm

Dimensions:
* S: 18.11 x 1.50 x 0.79 in / 460 x 38 x 20 mm
* M: 22.13 x 1.50 x 0.79 in / 562 x 38 x 20 mm
* L: 26.14 x 1.50 x 0.79 in / 664 x 38 x 20 mm
* XL: 30.16 x 1.50 x 0.79 in / 766 x 38 x 20 mm

Weight:
* S: 93 g / 3.28 oz
* M: 100 g / 3.53 oz
* L: 108 g / 3.81 oz
* XL: 115 g / 4.06 oz

Features:
* 360° visibility
* Integrated optical fiber and two high-powered LEDs provide full-length illumination
* Glow or flash
* Easy push-button operation
* Water-resistant
* High-quality metal belt-buckle style closure for quick and easy adjustment
* Strong metal D-ring
* Recharges in approximately 1.25 hours using micro USB cable (not included)
* Run time: 6.5 hours