Cs-137 sources are supplied as one inch plastic disks. Half life is 30.08 years. The small quantity of radioactive material is sealed in the plastic with epoxy to prevent leakage and contamination. The transmission window is sufficiently thin to transmit both beta and gamma emissions without undue absorption. Choices are:

1 microCurie
5 microCuries
10 microCuries

Please choose one. Custom Sources are available upon request.