The E61 bomblet was a anti-personnel bomb designed to be carried in the E133 cluster bomb. The cluster bomb was designed to hold about 540 of the E61 anthrax bomblets. The E61 held about of agent and a variety of pathogens could be used, generally anthraxspores. The E61 was perceived as superior to its predecessors, the M33 cluster bomb and its payload of M114 bombs. In fact, four of the smaller E61 bomblets produced twice the coveragearea of the larger M114 bomb. Upon impact the E61 would detonate releasing an aerosol of its anthrax spore laden slurry into the air of its target area.