Factory exhaust is 35mm OD where factory muffler slips on. Factory pipe is offset and angled from muffler; you'll notice inlet of muffer is angled and offset to match.
Option-1 Cone Adapter - Tip of cone-adapter is slightly large for factory exhaust (38mm). Shim with couple layers of soda/beer can. Due to offset of factory pipe, it will bring muffler very close to swingarm if it's an oval canister. Round mufflers will hit swingarm if used with cone-adapter.
Option-2 Angled adapter - this adapter does not need shimming to fit factory pipe. Its angled outlet will let you use any muffler with centre inlet.