A few more notes regarding the install. I dug several inches below the pipes that would be enclosed by the in-ground box and filled in the bottom with some leftover landscape rocks to the point where the box would be level with the ground. This also allowed an inch or two of clearance under the pipe with the Rachio Flow Meter so the couplings will be easier to access in the future.
When you are pushing the green couplings into the white couplings I would not push them fully into each other until you see how your measurements actually turned out. That gives you some additional flexibility in case you cut out more than the (measured twice) 15 inches of pipe. It’s was easy for me to push them closer together as I did the assembly. However, if you cut out 16 inches of pipe **(**too much!!) you may not be able to cover that space. I can’t say for sure how much you can make up for with the couplings, but less than an inch is possible, a half inch is pretty sure. Point is you can give yourself some flexibility by not shoving everything together to it’s limits when you first assemble the parts.