Prisoner Transport Systems window guards, and door caps are the perfect answer for guaranteeing prisoner safety and security. Allowing officers peace of mind during transportation. Our Window Guards install in less than 10 minutes, and are some of the most durable on the market. Prisoner Transport Systems Window Guards protect the vehicle, while extending its life and overall value. Every Officer knows this is an essential product to have when transporting a prisoner. And we have more than one style. Our Window Guards come in both steel as well as Poly-Carbonate.