The KD-7 bass drum trigger unit is based on an inverted mallet hitting a force-sensitive sensor. Suitable for all types of bass drum pedals, it requires no adaptation of your technique. The sensor is protected by a foam and resists the worst assaults. The foam does not affect the stability of the pickup or its incredible response. Dual pedal players can connect a second KD-7 to the first. This unit is suitable for all TD and SPD series modules as well as HPD percussion pads.