Diagram below show's the N16/B15's exhaust hangers. 4 exhaust hangers are used and there are 2 types/shapes of exhaust hangers but I know Nismo only make one version which is the same as the exhaust hangers used for the rear muffler - in red rectangles in the picture below.
I bought 3 Nismo exhaust hangers. One is for spare. Part number is 20651-RS230. Each hanger costs 1000 yen or RM 32+ or so depending on the MYR to Yen exchange rate. Don't forget to add shipping which came up to 1920 yen for me via EMS air freight. Got my Nismo exhaust hangers from IRS Japan.
Picture of the Nismo exhaust hanger.
Mounted on Sharkie. The rear exhaust hanger is stock as Nismo does not make an equivalent. Notice the big cut out on the stock hanger.
The other side.