would this work on my bike?

Im wanting to find a new Silencer for my bike i don't know if a spark Arrestor is the same thing i have a yamaha It 400D 1977 and it badly needs a new one. would this work?

Part (click here)

im new to buying any type of after market parts heres a diagram of how my muffler is

Diagram (click here)

and if you have any other ideas or parts please show me and give me a link to them thanks a lot!

Found a silencer http://www.motorcycle-superstore.co...encer-FMF-Power-Core-2-Big-Bore-Silencer.aspx