This is a nice, low cost low-pass filter that works great. My signal is VERY clean with this hooked up. No detectable harmonics, spurs, or other interference. I absolutely love the fact that you can hook a meter up to it so your power can be monitored easily on the fly. Accuracy seems good enough (please read below).
I have this mounted in a metal case on standoffs. RF Connections are made with RG316 coax to SO-239 connectors. I have the directional coupler hooked to a 150-watt panel meter that I found on rfparts.com
This was relatively easy for me to setup.