Sonic boom produces targets with high quality, non-hazardous, non-toxic and stable chemicals.The targets use a two part mixture that are easy to mix and easy to use.Simply mix and shoot.To ensure safety, shooters must be at least 50 yards from exploding target.To initiate explosion, rifle target must be struck with a center fire rifle projectile, weighing at least 40 grains and traveling at a minimum of 2200 fps (pistol rounds will not initiate these targets).For best performance, we suggest use of a fmj (full metal jacket) round.Size: 1 lbQuantity: 4 PackAuto Resetting: NoHazair: Yes