Now ULTRA has been upgraded to ULTRA Plus, the normal mode has been increased to 900MHz, and the sensitivity of ULTRA mode has been improved. The ZS406 version is used to replace the old ULTRA, the ULTRA mode has been increased to 5.4GHz, and the dynamics of frequencies above 3GHz have been improved. The ZS407 version is up to 7.3GHz, the LNA is effective in the full frequency band, and the high sensitivity covers all -FR1 bands. Since the LNA of ZS407 is an ultra-wideband LNA, in order to obtain flat gain in a frequency range, the noise figure is 2-3DB worse than that of ZS406 when it is below 20MHz. Please refer to the description of DANL below to reasonably choose a suitable model. The LNA of ZS407 is still effective above 7.3GHz, up to 14GHz, but due to the use of harmonic mixing above 7.3GHz, we cannot the reliability. If you need to use it beyond 7.3GHz, please evaluate it yourself. Specifications Hign-concerned Chemical: None : ELECTRICAL Covered frequency: 100k-7.3GHz (MHz) Application scope: spectrum analysis, signal measurement (The product appearance and printed words depending on the batch, but this does not affect use) Colour: As Shown Material: Metal Package Contents: 1set x spectrum analyzer with accessories Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.