This is a new reproduction flexible rubber seal for the evaporator lines to housing on 1973-75 Ford Trucks. This is the version that seals the housing the engine compartment. All AC trucks have this type of seal, and the original is almost always brittle and cracked. Note that this version has two 1/2" diameter holes and the holes are centered right to left. Later evaporators had one tube that was larger and the holes diagonally placed- and this won't fit well for those even though they look similar. Please look at your evaporator housing before ordering 

These are high quality rubber that will last for years. They are very flexible, yet durable.