Adding weight to your Lead Sled Shooting rest couldn't get any easier than with the Lead Sled Weight Reservoirs. These reservoirs feature a leakproof bladder inside a durable 600D nylon outer case. A wide mouth opening for easy filling with materials like water, sand, or gravel. The collapsible design folds out of the way when not in use. Compatible with Lead Sled 4 and Lead Sled DFT 3 each rest can hold 2 reservoir bags in the adjustable weight trays. The Standard Reservoir holds 1.2 gallons per reservoir (the Lead Sled 4 and Lead Sled DFT 3 rests hold up to 2 reservoirs), approx. 20 lbs. of water or 33 lbs. of sand total.