Kinesis SafariSack Beanbag Camera Support (Poly Bead Filled, Black, 4.2L)

I use it to shoot wildlife and birds from the vehicle and find it works well folded in half over the window or door. There is sufficient fill to keep the top of the fold padded and still wrap around the door or window. I use it succesfully with a 200 - 400 and a 150 - 600.

The 4.2 is the volume of filler (in liters) for the large bag. The 1.4 bag has a volume of 1.4 liters. So, the 4.2 is about 2 1/2 times bigger than a 1.4. I have both and the 1.4 is a bit small for long lenses or folding in half over a car window or fence rail.tree branch but very handy for a flexible support with smaller lenses. Hope this answered your question. Nice, well made product by the way and if you are taking it traveling say on a safari consider using buckwheat hulls for filler instead of poly - much lighter for packing,.