This equipment usually contains a sealed source of californium, a tritium/deuterium mixture, or an americium/beryllium mixture.
(This equipment; contains; a sealed source of californium, a tritium/deuterium mixture, or an americium/beryllium mixture; T:usually)
This equipment
contains
a sealed source of californium, a tritium/deuterium mixture, or an americium/beryllium mixture T:usually