Alpinestars Bionic Air MX Body Armour Back Protector Insert - Black Manual_Price allows the Crossfire 3 SRS

allows the Crossfire 3 SRS boot to accommodate riders with larger calves much easier than even the previous Crossfire 2 Boots

The SF Series devices can also easily connect to the Sena RideConnected App to intercom with a virtually limitless amount of riders over an infinite range

The lower leg inserts have zippered gussets to accomodate and provide close fit around various boot width sizes

but not recommend

Alpinestars Bionic Air MX Body Armour Back Protector Insert - Black Manual_Price allows the Crossfire 3 SRSAlpinestars Bionic Air MX Motocross Offroad Back Protector Insert Features: CE Certified Level 1 to the LATEST back protector standard (prEN1621 2: 2010) allowing a slimmer, more ergonomic design Slips in to your jackets back protector pocket to give you high levels of protection on the street without hindering riding comfort Innovative Dual Density Honeycomb Technology (DDH) combines two different honeycomb structures to offer lightweight impact