Using official Magnum 12® Rubber Bands is very important to the proper operation of your new gun. Magnum 12® bands are made to our exacting specifications and contain the highest rubber content available. Each gun lists a specific color (size) that will insure your gun performs to its highest potential. All bands are available in 4 bag sizes (1oz, 4oz, 8oz, 16oz). Please note that the bands are sold by weight and not by quantity. Therefore, larger size bands (Blue) will contain less bands per bag than the smaller size bands (Green).