The SafariSack has been in production for over ten years. It has been duplicated by others, but as they say, “copying is the best form of flattery.” We offer you a choice of fill. Poly beads are the most stable, but heavier than the buckwheat hulls. For lenses up to 200mm, the buckwheat is adequate. The 4.2 features a side gusset, allowing a thicker volume of filler when in half saddlebag style. The ends are slightly rounded for easier handling. D-rings on the ends for carrying over the shoulder with a shoulder strap (# Y215 is adjustable, unpadded & 1" / 25 mm wide). With the sewn-in strap, it can be securely fastened to the rack on the top of an Land*over which is common on safari...or your own mini-van or SUV! If you want a longer strap, get the # Y208. You can add water, sand or pebbles to use as a ballast to stabilize a tripod or light stand in the wind. We recommend the use of an optional liner for sand (R107) or choose the R425 SafariSack II for a simpler, less expensive ballast bag. Specifications Flat dimensions: 9.4 x 15.7" (24 x 40 cm) Empty weight w/o shoulder strap: 5.0 oz. (144 g) Poly beads filled weight (incl. the sack): 5 lbs. 8 oz. (2.5 kg) approx. Buckwheat hulls filled weight (incl. the sack): 1 lb. 7 oz. (660 g) approx. Recommended fill volume: 260 cu in or 4.4 qts (4.2 L) Black Empty SKU # R427-K or UPC # 680474822621, Khaki Empty SKU # R427-H or UPC # 680474822638, Black Poly SKU # R429-K or UPC # 680474822669, Khaki Poly SKU # R429-H or UPC # 680474822652, Black Buck. SKU # R428-K or UPC # 680474822645, Khaki Buck. SKU # R428-H or UPC # 680474822638