The Lee SW150 ND 0.9 Grad Soft filter will reduce the exposure by 3 stops. The purpose of the ND filter is to reduce the exposure evenly over the entire image. The filter is suitable for the Lee SW150 system. In this, you can use multiple filters simultaneously in the filter holder. The size of the filter is 150x170mm. Features of the Lee SW150 ND 0.9 Grad Soft * Suitable for the Lee SW150 system * Light Compensation: 3 stops * Ideal for landscape photography In the Box * Lee SW150 ND 0.9 Grad Soft 150x170mm Please note that this concerns the LEE SW150 series. These filters can not be used in combination with the kanon 100x100mm Foundation Kit System.