Genuine Daiwa Drag Click Spring.
 
This is the spring that sits under the spool, which generates the clicking noise when line is given out.
 
It fits the following reels
SS2600
SS1600
SS3000
Entoh 4500,5000,5500 silver model
Tournament TS5000T, TS5000BE, TS6000
SS9000
 
Daiwa Part Number B74-7701. Price per spring.