HP CRYSTAL DETECTOR Type 423A
Frequency range: 10 MHz - 18 GHz
Maximum Operating Input Power: 100 mW, peak or average.
Dimensions:
423A: 63 mm long, 20 mm diameter (2.46 in. long, 0.78 in. diameter).
8470A: 64 mm long, 19 mm diameter (2.50 in. long, 0.75 in. diameter).