The grooves in the deflector divide the flow into numerous sections of water. The off-center wobble further divides each section into relatively uniform-sized droplets. The rotary action evenly distributes these droplets over a large area, so water distribution occurs very rapidly. Wobbler sprinklers do not need to make a complete revolution to fill in the distribution pattern. This instantaneous coverage is gentler than stream driven devices and helps preserve soil absorption. Droplet size is determined by the deflector's specific groove configuration and angle. Wobbler technology was adapted for pivot sprinklers, solid set sprinklers, and nursery and greenhouse sprinklers. Senninger introduced the first high-quality in-line pressure regulator to the irrigation industry in 1966. Pressure regulators limit excessive and varying inlet pressures to a constant outlet pressure. This is done to maintain the desired performance of a sprinkling device. They accomplish this by automatically modulating their area of opening. By changing the area of opening as upstream pressures fluctuate, pressure loss through the regulator changes proportionally. This allows them to maintain the downstream pressure at a relative constant. Pressure regulators became popular due to their ability to maintain sprinkler's application patterns and droplet size despite fluctuating pressures in the system. When pressure and flow in an irrigation system spikes and goes beyond sprinkler design conditions, the sprinkler's application pattern will be affected and farmers could easily run into uniformity issues, over or under watering, and irregular crop growth. Pressure regulators prevent these issues. In the 1970s, Senninger worked with researchers and agricultural engineers at the Texas A&M University to develop a system that would reduce the energy requirements of a mechanical move system, while maximizing the use of both rainfall and applied irrigation water. In 1981, this joint effort resulted in the release of the Quad Spray, the first LEPA (Low Energy Precision Application) sprinkler for center pivots. Using center pivot and linear move machines, LEPA sprinklers maximize the amount of water delivered to roots and minimizes water pressure, and therefore energy use, through a combination of sprinkler heads that avoid wetting the crop canopy and conservation tillage practices that preserve soil moisture and reduce runoff. True LEPA systems use low-pressure bubble heads to deposit water directly into furrows just 8 to 18 inches above the ground. With the heads closer to the crop, the water avoids the hitting leaves. Water does not come in contact with plants and fruit susceptible to waterborne diseases and nearly all of it is absorbed by the soil.