The indicated address at 133 S. Dupont Hwy in New Castle DE is actually the "Relax Inn" (http://www.relaxinn-de.com/) and not the Knights Inn.
This is an old 50-60s vintage motor lodge that has seen far better days. It is a great deal for the money and is very clean, but expect major parts of the infrastructure to not work at any given time. When we stayed there, the single ice machine serving the entire facility was broken, and they offered tiny bags of ice from the cooler in the office. Also, the fan in the bathroom looked like it hadn't actually functioned in years.
Overall, it wasn't too bad. The TV and wi-fi worked (although one of us had trouble getting a connection- weak signal). It was clean, if cramped, and a modern traveler might have problems with limited power outlets.
It looks like this place was probably renovated in the 70s-80s, but it is due for another round of fixes and upgrades. Because of many mechanical problems, I down-graded this one a bit, but for the money, it wasn't bad, and the stay was tolerable.
One plus- we had tried the nearby Motel 6 at the I-95 off-ramp, only to find it in a high-crime ghetto. We had absolutely no such problems here, and felt completely safe. It is convenient to many fast-food restaurants, gas stations, and I-295.