Malkoff MDM4 M91T SureFire Millennium Adapter




This turnkey package includes a Malkoff MDM4 Adapter and a Malkoff M91T Drop-in.  The output is 1040 Lumens momentary and 750 Lumens continuous.  The M91T provides a tight, focused beam with ample spill.  The beam is 19,000 Lux at one meter.  It will illuminate objects out to 900+ feet.  The current draw is approximately 1400ma at 9 volts. The full output runtime is approximately 30-45 minutes on three CR123 primary batteries with a nice long taper as voltage drops.  The LED is a cool white (6200K) Cree XP-L HI.

The Malkoff MDM4 Adapter will fit most Surefire Millennium Series Lights including the M3, M4, M6, M500, M961, M962, M900, and M910.  The M900AB and M910AB (rail mounted vertical grip weapon lights) may additionally require a spring for the tailcap so the batteries can be installed with the negative toward the tailcap.  Please request the spring in a follow up email to  after checkout.  It will be included in your order for no charge. 

This Item is Covered by Our Lifetime Warranty. 


Things to Know Before Purchase:

The maximum input voltage for the included M91T is 12v.  It is suited for use with up to four primary CR123 batteries or three rechargeable Li-ion cells.  It will work in the Surefire M6, as the M6 is actually a 9v light even though it has 6 batteries.

The MDM4 WILL NOT FIT the Surefire M951.  For that model please see the Malkoff M61.

The MDM4 will allow for the use of a Malkoff M Series Drop-in in any Surefire incandescent light which uses the stock incandescent MN10, MN11, MN15, MN16, MN20, MN21, MN60, or MN61 lamp assemblies.  Please check your bulb before ordering.

The MDM4 will physically allow any Malkoff M Series Drop-in to fit the above listed lights.  However, please be sure to check the voltage requirement of the chosen Drop-in against the voltage of your light for compatibility. 

WARNING: This light is capable of causing eye damage at close range. Please use the light responsibly!!!


Made in the USA. Some parts not domestically sourced.


SureFire, LLC, which manufactures and sells Surefire® flashlights is not associated in any way form or fashion to Malkoff Devices. SureFire, LLC, does not manufacture, sponsor, warrant, or endorse any Malkoff Devices product advertised on this website. The use of the Surefire® trademark, a registered trademark of SureFire, LLC, is strictly for the purpose of identifying the host flashlight for the Malkoff Devices products advertised on this website. All other trademarks, copyrights, and graphics or text not owned by Malkoff Devices or any of its related companies that appear on this site are the property of their respective owners, who may or may not be affiliated with, connected to, or sponsored by Malkoff Devices.