What is the black putty called that seals up the ac unit?

I have changed out my heater core and had to move the ac unit.The ac unit is sealed up the fire wall ,I broke the seal when I unbolted it.I need to make the seal back,whats it called ,does any auto parts sell this stuff.

Man the heater system is really going to blow:D cant wait to turn it on .I also got a new blower for it also.The new heater core has bigger passages through it,so I am thinkin it will flow more air.:)

It kinda looks sprayed on.There is the tape stuff wraped around the pipes.that is still intact.The stuff I need is where the housing meets the fire wall all away around the housing.