This exhaust fits the early slab side GSXR-1100 (1127) air-cooled motor. I believe it is for 89-92 as that header is shown by Supertrapp as a 4-1. The 93-97 is shown as a 4-2-1.

This exhaust has a nice patina and is in overall good shape. It is missing the clamp for connecting the muffler to the header.