K&K high-voltage brushes with activation sensors - extension kit 2 pcs for the M9900 marten repeller, multi-contact +/-, fits the existing cable
- The K&K extension kit contains 2 multi-contact high-voltage brushes with activation sensors for the M9900 marten repeller. You slide them onto the existing cable and protect more entry points to the engine bay.
This K&K kit extends the M9900 marten repeller with 2 more high-voltage brushes with activation sensors. The M9900 works in sleep mode and builds up high voltage only when a marten touches a brush. That is why extra brushes need the same sensors as the brushes in the basic set. The kit fits the M9900 only. You mount it on the high-voltage cable that is already in the vehicle.

Key features
- 2 multi-contact high-voltage brushes with activation sensors
- plus and minus strands of stainless steel
- for the K&K M9900 marten repeller only
- mounted on the existing high-voltage cable
- no vehicle ground needed, they also work on plastic covers
You slide the brushes onto the cable and fix them by tightening the Phillips screws. The screws tap into the cable and make contact, and cable ties hold the brush in place.
When to add brushes
- a large engine bay with many entry points from below and the sides
- the marten uses routes other than those covered by the 4 brushes of the basic set
- you want to protect more wires, hoses or the insulation mat
- the vehicle is parked where martens are common
Installation
- the maker recommends installation in a workshop, and a lift makes low entry points easier to reach
- set the M9900 to OFF and disconnect the plug before working, then wait about 3 minutes for residual voltage to discharge
- slide the brushes onto the high-voltage cable and place them at entry points, paths and spots at risk of bites
- keep at least 10 mm from other conductive parts and mount the brushes at an angle so water can drain
- fix the brushes with cable ties without overtightening them
- tighten the Phillips screws to tap into the cable and make contact
- the cable end must not stick out beyond the last brush, as this risks a short circuit
- route the cable away from hot and rotating engine parts
Check after installation
After extending the system, check the M9900 as on first start-up: hold the bonnet switch pressed and toggle the switch from OFF to ON 3 times. If both LEDs flash 3-5 times, the unit works and goes into sleep mode. If the high-voltage LED does not flash, check that no brush touches conductive parts and that the screws have tapped the cable properly.
Safety
The voltage on the brushes is not dangerous for healthy people, but the touch is unpleasant. People with heart conditions or a pacemaker should not touch the brushes. Keep the brushes clean and protect the whole unit from excessive heat.

Why only for the M9900
The M9900 sleeps most of the time and is woken by the sensors in the brushes. When a marten touches a brush, the unit builds up high voltage within a fraction of a second. Brushes without sensors would not wake the M9900, so this kit is made for that model. For the M9300, M9700 and M4700B there is a separate kit with 4 brushes.
K&K accessories and other repellers in our shop
- K&K M9900 marten repeller - sleep mode and 4 brushes with activation sensors
- K&K extension kit with 4 brushes - version for the M9300, M9700 and M4700B
- K&K M9300 marten repeller - 6 high-voltage brushes, no ultrasound
- K&K M9700 marten repeller - 360° ultrasound and 6 high-voltage brushes
- K&K marten scent mark remover 500 ml - for cleaning the engine bay before installation
Technical data
| Parameter | Value |
|---|---|
| Manufacturer | K&K (Germany) |
| Model | M9900-KIT |
| Type | extension kit with high-voltage sensor brushes |
| Number of brushes | 2 |
| Brush design | multi-contact, plus and minus strands, stainless steel, activation sensor |
| Mounting | slides onto the cable, Phillips screws tap into the cable |
| Fits | K&K M9900 only |
| Colour | red |
Questions and answers
Does the kit fit the M9300 or M9700?
No. Brushes with activation sensors are made only for the M9900. For the M9300, M9700 and M4700B there is a kit with 4 brushes.
How many brushes can the M9900 have?
The M9900 comes with 4 brushes, and the maker provides for extending it with the 2 brushes from this kit.
Do I need an extra cable?
You slide the brushes onto the high-voltage cable that is already installed. Place them so the cable reaches all the chosen spots.
Will extra brushes shorten battery life?
The M9900 builds up voltage only when a brush is touched and sleeps the rest of the time. Keep the brushes clean, because dirt increases the current draw.
Manufacturer
K&K Handelsgesellschaft mbH, Gewerbepark Hardtwald 14, 68723 Oftersheim, Germany.








