This is a 100W 50 ohm dummy load using a non inductive resistor MHP100-500F and a N type chassis connector. It has 1.6 SWR in 70 cm ham band.

I do not recommend to build it now, it is better to use resistors a little more expensive but with much higher frequency up limit. The cooler  is small for continuous 100W dissipation, you have to use a bigger one.