Superior audio performance as well as physical comfort can both be found in Sena's premium HD Speakers, which are included. I have owned and used Sena intercoms for many years. Set up with my riding buddy was done entirely through the iPhone app which was easy.
eBay
Fodsports FX7 Mesh Motorcycle Intercom Bluetooth Helmet Headset,10 Rider 2000M,FM,BT5.4
Aliexpress UK
Sena Mesh + adapter. Used a few times. easy to use and was handy. But upgraded helmet so not required anymore.
eBay
For SENA 50S Motorcycle Bluetooth Headset Box Protection Stickers Colorful Earphone Decoration Decals Waterproofing
Aliexpress UK
Superior audio performance as well as physical comfort can both be found in Sena's premium HD Speakers, which are included. The ST1 is a breeze 1 button to link to your smart phone. Sena app is just as simple to use.
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1000mAh 3.7V Wireless Headset Battery for Sena SRL2 SRL1 SRL-01 (SP51) SHOEI Neotec II GT-Air II J-Cruise II PTC802050 2 3 wires
Aliexpress UK
Sena's premium HD speakers are redesigned and optimized for both physical comfort and unmatched audio performance. After using a cardo unit the sena 30k is a totally different experience. Couldn't ask for any more than that.
eBay
EJEAS Q8 Motorcycle Mesh Intercom with EUC Remote Walkie Talkie Bluetooth Interphone Headset for 6 Riders with Bluetooth 5.1
Aliexpress UK
This is an upgrade from my 50s and sound level and quality is outstanding. Intercom system featuring Wave Intercom tech with 2nd gen speakers, dynamic LED and integrated torch. Sena 60S best yet. Brought this after having a 50s The 60s blows it out of the water on it’s superior sound quality it’s a breeze to set up and updates are easy to install over WiFi from your phone.
eBay
Helmet Headset 10 Riders 2000M Intercom Motorcycle Mesh Intercom Hands-Free Calling Bluetooth 5.3Ip67 Waterproof 1200Mah Headset
Aliexpress UK
Sena's premium HD speakers are redesigned and optimized for both physical comfort and unmatched audio performance. Works perfect in different weather conditions. Using now more then year and still go strong.
eBay
ASMAX F1 Motorcycle Bluetooth Headset 10 Riders Mesh Helmet Communication Systems AI Voice Control Intercom 50min Charging
Aliexpress UK
(6 riders @ 1 mi / 1.6 km intervals). Bluetooth Intercom: Range of up to 1.2 miles in open terrain. Bluetooth 5.0. Head unit only. NO ACCESSORIES! Used like new, fully working and in good condition.
eBay
2pcs Fodsports FX7 Mesh Motorcycle Intercom Bluetooth Helmet Headset,10 Riders 2000M,FM Radio,Dual Bluetooth 5.4
Aliexpress UK
Boom Microphone: length 85 mm. Headset Profile (HSP). Can extend up to 1.6 km (1 mile) between a minimum of 6 users. Advanced Audio Distribution Profile (A2DP). - Main Module: 164 mm x 120 mm x 142 mm (6.5 in x 4.7 in x 5.6 in).
eBay
1/2Pcs EJEAS Q8 Mesh Intercom Motorcycle Helmet Bluetooth Headset For 6 Rider BT5.1 Mesh Communicator IP67 Music Sharing Mesh3.0
Aliexpress UK