This is the high-sensitivity version of RMT's fiber test combo — built for the low light levels of real-world access networks.
The ST800K-C power meter reads down to -70 dBm, deep enough to measure the faint signals at the far end of splitter-heavy FTTH legs, long telecom spans, and receive-side measurements where a standard meter just reads LO. (If you work CATV or PON transmit plant with hot signal levels, see our companion kit with the ST800K-A meter, which measures up to +26 dBm.)

Paired with the ST815 laser source producing stable 1310 nm and 1550 nm output from a single port, the kit covers daily fiber work end to end: absolute power readings in dBm at any point, and true insertion-loss testing using the meter's relative dB mode — zero the reference at the source, measure at the far end, read the loss directly.
Tone detection and generation at 270 Hz, 1 kHz, and 2 kHz makes identifying one fiber in a crowded splice case straightforward.

Rugged field-ready housings, big backlit displays, auto-off, 150-hour meter battery life on common AAs, and interchangeable FC, SC, and ST adapters included.
A complete, affordable loss test set for new techs and a solid backup kit for seasoned crews.

• Calibrated wavelength points: 850, 1300, 1310, 1490, 1550, and 1625 nm (800-1700 nm test range)
• Absolute power in dBm or xW; relative power (loss) in dB
• Detects and indicates 270 Hz, 330 Hz, 1 kHz, and 2 kHz tone-modulated light for fiber identification
• InGaAs detector; 0.01 dB logarithmic resolution
• Interchangeable FC, ST, and SC adapters included (FC pre-installed)
• Large backlit LCD; auto-off; low-battery indication; runs 150 hours on 4x AA

• Stable dual-wavelength output: 1310 nm and 1550 nm from one port
• Continuous wave (CW) plus 270 Hz, 1 kHz, and 2 kHz modulated output for fiber identification
• FC, SC, and ST optical interfaces
• Backlit LCD, auto-off, battery voltage display

• 1x ST800K-C Optical Power Meter (-70 to +3 dBm)
• 1x RMT-ST815 Laser Source (1310/1550 nm)
• 2x FC adapters (pre-installed), 2x SC adapters, 2x ST adapters
• 6x AA batteries and 2x operation manuals

• Meter Range: -70 to +3 dBm
• Wavelength Range: 800-1700 nm; calibrated at 850/1300/1310/1490/1550/1625 nm
• Detector: InGaAs
• Resolution: 0.01 dB (log); 0.1% (linear)
• Source Output: 1310/1550 nm, CW or 270 Hz / 1 kHz / 2 kHz modulated
• Connectors: FC, SC, ST
• Meter Battery Life: 150 hours (4x AA)
• Operating Temp: 14°F to 122°F (-10°C to +50°C)
• Warranty: 1 Year