Greentronics has boom height control systems that work. Simpler to install, fast effective service, and ISO compatible. Contact Brian Langendoen 306-981-0024 I have systems in stock and can deliver. Older systems can now be upgraded. Pre-order to save an additional 10%! NEW RH400 system upgrades include: Choose from 3 Operating modes - bare ground, partial canopy, full canopy - for optimum performance and stable operation. Smart self-calibration. Automatically adjusts to sprayers hydraulic performance. Ability to control proportional (PWM) valves. Long range sensors, competitive prices, 2-5 sensor systems. Fits ALL sprayers with electric-over-hydraulic controls. Other products available. Check out www.greetronics.com