Outdoor monitor or vehicle monitor detectors.

7866 cm³ (480 in³) plastic scintillation detectors with 0.33 cm (0.13 in.) lead shielding in weathertight housings

These detectors can be used with the Ludlum 375P Waste Monitor System or any other meter with adjustable high voltage.

The picture shows both detectors, they are sold individually.  $1500/ea