Skip to Main Content
Last Chance! Icon Select Helmets 25% Off Ends In:  

Looking for something else?

Fast Lane


This item is available as a Blem/Refurb. These are items that cannot be sold as "New" merchandise and are limited to stock on hand. See the product details for a description of the product's condition.

Ships Free to Cycle Gear Stores!

Ship to an Address:
Please select a to view availability.


Pick-up in Store:
Cycle Gear Springfield Check Nearby Stores

The Cycle Gear Difference
  • Free Bluetooth Installation Find a Store
  • 30-Day Best Price Guaranteed
  • Free Shipping Over $69.99
  • No-Hassle Returns View Details

HJC Smart 21B Bluetooth Headset by Sena Resources

HJC Smart 21B Bluetooth Headset by Sena

Whether you are riding solo on the open road or are cruising as a part of the pack, a Bluetooth headset can truly enhance your experience. HJC and Sena came together to make it even easier to integrate Bluetooth communication into your helmet with the Smart 21B Bluetooth Headset. You can keep in touch with your buds and even share music thanks to the 4-way universal intercom with a max range of 1.6km (0.9 miles.) Universal intercom compatibility connects to other brands of headsets.

Bluetooth 5.1 technology allows audio multi-tasking to seamlessly blend incoming audio from multiple sources and optimal connectivity. HD speakers come standard so you get top-notch clarity right out of the box and you never miss a beat. The Smart HJC 21B is designed to seamlessly integrate with the RPHA 91, RPHA 71, RPHA 31 and i90 helmets, so install is a breeze and the aesthetic is undeniably sleek.


  • Power time: Up to 22 hours
  • Working distance: Up to 1.6km (0.9 miles) in open terrain
  • Smart HJC BT App for your phone allows for quick and easy setup and management
  • SMART HJC Device Manager for your PC allows you to upgrade firmware and configure settings
  • Compatible with Sena remote control devices (sold separately)


  • Bluetooth 5.1
  • Universal intercom compatibility connects to other brands of headsets
  • Pairs with mobile phones, Mp3 players, GPS devices and Sena SR10 Two-Way Radio Adapter
  • Four-way intercom
  • Music sharing
  • Hands-Free Profile (HFP)
  • Advanced Audio Distribution Profile (A2DP)


  • HD speakers for crisp and clear audio quality
  • Audio multitasking allows you to hear the audio from two features simultaneously
  • Advanced noise control
  • Audio equalizer for dialed in audio preferences
  • HJC Helmet Compatibility:
  • RPHA 91
  • RPHA 71
  • RPHA 31
  • i71


  • Headset main unit
  • Wired boom microphone for modular and open face helmets
  • Microphone sponges for wired boom microphone
  • Wired microphone for full face helmets
  • Hook and loop fastener for wired microphone
  • USB power and data cable
  • Screws
  • Allen wrench
Read More
Fitment Notes & Exceptions

Notes from the manufacturer:

  • Intercom range will vary depending on obstacles (person, metal, wall, etc.) or electromagnetic environment.
  • Please make sure to take off your headset-installed helmet while charging. The headset automatically turns off during charging.
  • Any 3rd party USB charger can be used with HJC products if the charger is approved by either the FCC, CE, IC, KC, or other locally approved agencies.
  • Use of a non-approved charger may cause fire, explosion, leakage, and other hazards which may also reduce the life time or performance of the battery.
  • The headset is compatible with 5 V input USB-charged devices only.
  • If you pair your GPS device via GPS Pairing, its instruction will not interrupt your Intercom conversations, but overlay with them. Bluetooth intercom conversations will be interrupted by GPS instructions.
Product Style Item # Store SKU Manufacturer Product # Availability
Product Style Matte Black Item # 10305335 Store SKU Manufacturer Product # BT021B00MBK0 Availability In Stock: Ships within 24 hours
Join now & get rewarded!

Get Free 2-Day Shipping and $15 + 5% RPM Cash on this order.

Already enrolled in RPM? Link your existing membership here.

We're always looking to get better for our customers. Tell us what you like, what's missing, or what's broken.

Leave Feedback