You can see the description better in this link.
http://www.twistedthrottle.com/plug-n-play-wiring-kit-for-stebel-compact-nautilus-airhorns
Easy and inexpensive Plug-N-Play wiring kit for Denali SoundBomb Compact Dual-Tone Air Horn & Stebel Air Horn that does not require any cutting, soldering, slicing or crimping as long as the original horn has blade-style electrical connections. Clip one lead to your original horn trigger wire, one lead to battery ground, one lead to battery positive, and plug in your horn's relay.
If the original horn does not have blade-style electrical connections, the original horn connector needs to be removed and replaced with female spade connectors in order to use this harness. If your BMW does not have spade connectors please order the DENALI wiring adapter for BMW motorcycles (in the drop down menu above) to avoid modifying your wiring harness.
For use with Stebel Air Horn & Denali SoundBomb Compact Dual-Tone Air Horn, but can also be used with other replacement horns.
Features:
No cutting, soldering or crimping for application with blade style horn connections
Extra connections for custom applications
5.5ft harness length
30amp Mini inline fuse
Inline relay socket
Protective vinyl sheath
Weather resistant
Includes:
Complete Harness with inline fuse and relay plug as well as pre-connected ring terminals and female blade connections
2 posi-tap inline wire connectors for custom applications
2 male blade crimp on connectors for custom applications
2 female blade crimp on connectors for custom applications
4 wire zip ties
30amp Mini Fuse for pre-connected inline fuse holder
Fits:
Motorcycles with blade style horn wire connections
Please Note: A 5 Pin relay is not included with this kit. A relay is provided with the purchase of a DENALI SoundBomb Compact & Split horn. If using this harness with another horn, please use this 5 pin relay.