X-Large: 24" - 28" (61cm - 71cm)', 'FULL-LENGTH ILLUMINATION - Two ultra-bright LEDs and an integrated optical fiber illuminate the full circumference of the collar without a loss of brightness, providing 360° visibility while on night walks, hikes, camping, and at the dog park', 'HIGH-QUALITY METAL BUCKLE - The integrated premium hardware features an adjustable belt-buckle style closure made of brushed black metal for easy access, sleek style, and lasting strength', 'QUICK & SIMPLE RECHARGING - The NiteDog collar stays illuminated for 6 hours and 30 minutes on a single charge, recharging via micro USB in just 1 hour and 15 minutes to make daily use simple and practical', 'RUFF & TOUGH WATER RESISTANCE - This light-up collar will keep shining through inclement weather, ruff-housing, and splashing around, allowing your furry friend to stay seen and safe through it all']