This is a PathBlazer headlight modulator.  It is made by Kisan Technologies and is designed to modulate the headlight bulbs for better visibility.  This is a complete plug and play unit and meets federal DOT standards in all states.  This will fit the cruisers listed below;

P115W-S unit is totally self-contained. There are no hidden boxes or switches. There are no wires to cut or splice.

P115W-S unit is designed for 3-pin H4 or a Japanese H7 2-pin style headlamps. It's 1.25" (32mm) round, and requires NO ADDITIONAL SPACE after it's plugged on the back of the bulb.

pathBlazer circuit modulates the hi-beam current - from 100% ON to about 17% OFF. This is accomplished by using a p-channel MOSFET, which is inherently safe. The MOSFET is designed to fail in the ON state. For additional safety, the circuits DO NOT utilize the lo-beam whatsoever!

MAX power rating is 115 watts. DO NOT EXCEED!

P115W-S comes with a detachable daylight sensor, which simply plugs into the pathBlazer. The daylight sensor functions as a switch; it stops modulation when it cannot see enough daylight. Since the internal circuitry is controlled by a microprocessor, it allows for customizable features.

Programmable Daylight Sensor

If you turn the high beam on and then turn the ignition on three times quickly, the sequence is interpreted as an active command to change the sensitivity.

Current software version v.823A allows 8 linear steps between the high and low end.

The daylight sensor has a low frequency filter to avoid false triggering. Please note that florescent lamps may not trigger the sensor - it needs constant incandescent light.

pathBlazer uses a soft-switching technique. It throttles the current flow through the bulb filament, so that there's no "thermal shock" due to a sudden inrush of current, which can damage the bulb filament or shorten its life considerably. This is far superior than maintaining a small voltage!

Select hi-beam to modulate - as long as there's sufficient daylight. If you enter a tunnel or if it gets dark, it will stop the modulation of the hi-beam and stay ON steady. Select lo-beam to end modulation.

This will fit model:
Honda Shadow VT600
Honda Shadow VT750 ACE, Aero and Spirit
Honda Shadow VT1100, ACE, Aero, Sabre and Spirit
Kawasaki VN800
Kawasaki VN1500 Classic, Drifter, Meanstreak and Nomad
Kawasaki VN1600 Classic, Meanstreak and Nomad
Kawasaki VN2000 Vulcan Classic
Suzuki Boulevard C50 and M50
Suzuki Intruder VS800/S50
Suzuki Intruder VL1500/C90
Suzuki Volusia VL800
Yamaha V-Star 650 Classic and Custom
Yamaha V-Star 1100 Classic and Custom
Yamaha Road Star
Yamaha Royal Star