They are very Thin & Light, however they do require SOME room.
Most helmets have a small pocket by the ears that the speakers fit nicely into.
Not all do however.
For the ones that don't have enough room, most guys usually peel back the liner a bit,
trim/shave just a bit of the foam behind the liner, to make room for the speakers, re-install the liner, & then install the speakers.
(You want little to nothing between the speakers & your ears.)
CASE INSTALLATION:
Test fit case and Visor WYE cable with Visor prior to finalizing Case installation location.
The Left side of your helmet is highly recommended for area of installation.
Clean area of install with rubbing alcohol, allow to fully dry.
Peel backing from mounting Velcro & stick to helmet.
Rub well into place with your fingers to insure a good bond.
Attach TRAIL JAMZ case to helmet by pressing into place.
Can always peel apart Velcro & re-adjust case placement as required.
You want the zipper handle to be towards rear of helmet when zipper is closed.
VOLUME CONTROL INSTALLATION:
You want the Volume control mounted so you can easily operate it with your Left Hand.
The Left side of your Helmet mounted low, usually mounted on the bottom edge works best.
Using Scissors, cut the soft side(loops) of Velcro to fit the side of your Volume Control.
Clean area of install with rubbing alcohol, allow to fully dry.
Peel & stick on side furthest away from the volume control wheel.
(Volume Control Case usually has 2 screws on this side. This makes it easier to use control.)
Clean area to mount Hook Half of Velcro for Volume Control with rubbing alcohol.
Peel backing from Hook half of Velcro, align, and press into place.
Rub into place with fingers to insure a good bond.
WIRES:
Neatly tuck any excess wire behind your helmet liner.
You can also tuck them under/behind the rubber edging on your helmet.
The rubber edging is especially useful near the Volume control.
MP3 PLAYER:
Adjust the EQ as noted below.
Adjust the Volume to max or with-in a few presses of max.
(You use the player volume to adjust the absolute maximum volume level you want as your ride.)
You will use the external helmet mounted volume control to adjust volume as you ride.
Plug MP3 into the Mini B USB charging cable from your power supply.
Use the connection coming out of the same end as the Blue Power in RCA Cable.
The other USB charging connection is for the optional Amplifier.
Plug 1/8" stereo plug from speakers into MP3 Player.
Make sure plug is FULLY seated into player.
General use is to set the Player as follows:
(Most of the settings are Under SETTINGS then MUSIC SETTINGS)
Set to REPEAT ALL.
Set to PLAY ALL. (You will not set to Play All if you use Playlists, you will select Playlists to play then.)
Set EQ as noted below.
ENJOY YOUR TUNES ! : )