The detector consisted of a tank filled with 167 tons (50,000 gallons) of mineral oil and 14 pounds (6.4 kg) of b-PDB (2-(4-tert-butylphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole) organic scintillator material. Cherenkov light emitted by particle interactions was detected by an array of 1220 photomultiplier tubes. The experiment collected data from 1993 to 1998.