Radiodetection Standard Sonde (33 kHz) The Radiodetection Standard Sonde (33 kHz) is a compact, self-contained transmitter designed for locating non-conductive underground utilities such as pipes and ducting. Operating at 33 kHz , it produces a strong, consistent signal that can typically be located to depths of up to 16 ft (5 m) using compatible Radiodetection locators. Measuring 1.53 in × 4.13 in (39 mm × 105 mm) , this battery-operated sonde is well suited for use with a Flexrod or similar push rods . The Standard Sonde is also available in 512 Hz and 8 kHz variants to match different locating systems and job requirements. Part Number: 10/SONDE-STD-33 Key Features 33 kHz transmit frequency Also available in 512 Hz and 8 kHz Locatable to 16 ft (5 m) Compact, self-contained, battery-operated design Size: 1.53 in × 4.13 in (39 mm × 105 mm) Compatible with Flexrod or similar push rods Strong signal for reliable locating of non-metallic utilities Ideal For Utility locating professionals, sewer and drain contractors, and municipal crews tracing non-conductive pipes, ducting, and underground routes in confined or shallow environments.