I have used the 4’ Premier netting for a few years. If they wanted to my full-sized chickens could easily fly over it, but they generally don’t. It’s all about them being motivated to fly over.
I raise a lot of cockerels and pullets with the main flock. With one exception the only time I ever found a chicken outside the fence is when a cockerel gets trapped against the fence when fighting another cockerel and goes vertical to get away. They were not trying to fly over the fence, just trying to get away from a losing fight. I did find a hen outside once. I assume she was trying to get away from an amorous rooster or cockerel and went vertical when trapped against the fence.
One trick I’ve learned is that layout makes a difference in how many chickens fly over the netting. Try to set it up wide open. Avoid sharp corners where a chicken can get trapped pretty easily. Don’t go below a 90 degree corner if you can avoid it and rounding them off even more helps a lot. Also, avoid long narrow areas. Chickens have to walk past each other in these and narrow sections seem to instigate more conflict.
Baby chick up to about 6 to 7 weeks old (full sized fowl) can just walk through the fence. If chickens touch the electrified section with their combs or wattles they will get shocked but feathers and down insulate them from the electricity. These chicks are small enough to just walk through without getting shocked. When an adult chicken hits the netting with comb or wattles they get shocked and jump back but that is kind of rare. They do eventually learn to not eat the grass and weeds right at the netting.
A chicken is not going to get shocked if they try to fly over the netting and hit the netting. To get shocked an animal has to complete the electric circuit; from the netting, through their body, and into the ground. An animal’s fur will protect them from getting shocked since it provides insulation too, but practically any predator will not just run through or jump over the fence. They go up to the barrier and investigate it, usually with tongue or nose. They can get shocked when a tongue or nose touches a hot wire and their feet are on the ground to complete the circuit. Generally all it takes is for a predator to get shocked once and they give that netting a wide berth from then on.
I’ve chatted with Premier a couple of times about their netting. I find them quite helpful but they don’t volunteer the information that their netting can be pretty ineffective in the snow. You have to ask. A wet snow will short it out. A dry snow will insulate the predator from the ground. The netting will still keep the chickens contained and the predators that have been shocked in the past will still respect it, but there are new predators coming along all the time. People abandon dogs in the country or raccoons, foxes, coyotes and such are being weaned and striking out on their own. Still, I’ve never had an attack from a ground-based predator since I put it up and just one loss from an owl when I was late locking them up in the coop one night.
My current is over 7000 volts but the amperage is pretty low. Amps is the most dangerous part of that. If I grab it and brace myself I can hold on but if it surprises you then you will let go. The big safety factor is that the current is not steady, it pulses maybe 50 times a minute. If it were a steady current the animal or you would not be able to let go, but since it pulses they automatically let go if they can. Over the years I have found two snapping turtles, a possum, a snake, and a couple of frogs tangled in the netting where they could not let go. One snapping turtle walked away when I untangled it from the netting. It probably had not been there a real long time but was kind of paralyzed. It recovered. The possum was still alive when I found it, but paralyzed. I dispatched it with an ax, the electricity was not what killed it. The others were dead when I found them. They were tangled up and could not let go. They had probably been there a long time.
A big problem with the netting is that weeds and grass will grow up in it and short it out when they are wet from dew or rain. I’ve had leaves or cut grass wash up against it in a washing rain and short it out. There is some maintenance involved. Weed eaters and lawn mowers are especially dangerous around that netting. According to Premier those are the biggest cause of problems with the netting. Depending on the time of year and how much rain I get I may need to mow that growth weekly or may be able to go a lot longer. If your ground is really rocky moving it can be more of a pain but even then it’s not really bad. One person can move it but there are times when two people can make it go a lot faster. The bundle of fencing is not only heavy, it’s awkward to handle.
As Egghead mentioned the netting can sag and let a hot wire touch the ground, especially if your ground is not perfectly flat. The hot wires are the horizontal ones with the exception of the one right at the bottom. I take a stick with a notch on it and prop the netting up to avoid this. You can only tighten the netting so much, sometimes it still sags.
I’ve found the netting to be really effective at containing the chickens and keeping ground based predators out. There is some maintenance and a bit of a learning curve involved though. It’s not an install it and forget it thing.