black one. sorry, don't have the quotation for white one
oh. the last one is for 2.5HP..... typo

i'm not sure too, only heard it from shawnsean. hope he can answer u

Inaba piping insulator is white color while the standard insulator is the black one. The black one is more like a sponge so after a few years it will become flaky and can be peeled off easily. Since its concealed and for own stay I paid more to get inaba piping. Apparently the copper is also thicker and stronger. One contractor showed me both inaba and normal and ask me to touch and bend it to feel the difference. I heard cases of old building where water was leaking from the concealed air cond piping into the electrical wiring and causing short circuit. Had to hack the wall to troubleshoot