SRL-EXT. Communication by SENA meets SHOEI performance with SOUND BY Harman Kardon. The SRL-EXT delivers Mesh and Bluetooth intercom plus seamless smartphone connectivity across SHOEI full-face helmets. Features: Designed for SHOEI Helmets: The SRL-EXT is designed for universal fitment across SHOEI full-face helmets, offering a streamlined integration that complements the helmet's shape. The main module installs on the left side, while the external battery mounts on the right, maintaining a balanced, low-profile setup without interfering with comfort or aerodynamics. Hands-Free Convenience with Sena's Voice Commends: