Sena SF4 HD Bluetooth Headset YCRF_bicycle_helmets Adult sizing:S/M 32-40" ChestM/L 36-44"

Adult sizing:S/M 32-40" ChestM/L 36-44" ChestL/XL 40-48" ChestXL-2XL 44-52" Chest

The foam is covered with cordura and has CFR rubber logos sewed on for a rugged finish that can withstand anything

Heavy duty ball joints feature steel on steel design with an adjustable cap and a grease zerk fitting

5-inch LCD monitor

Slip on neoprene cuff design for unrestricted fit at wrist

Sena SF4 HD Bluetooth Headset YCRF_bicycle_helmets Adult sizing:S/M 32-40" ChestM/L 36-44"SMALL GROUPS CONNECTIVITY & COMMUNICATION The SF4 is the perfect device for riding with friends by providing connectivity for small groups. The SF4's 4 way intercom has a range over 1. 2 kilometers (. 80 miles) so you can easily stay connected with your group in open terrain. The SF4 also uses smartphone connectivity, allowing for music streaming, taking and making phone calls, and hearing turn by turn GPS directions. Most importantly, riders can