It is a urethane arbor to fill the space between the blank and the reel seat. Considering the weight and sensitivity, it is best to use a urethane
Urethane Arbor for Reel seat (UAG-13mm/15mm )
Polyurethane Reel Seat Arbor for Reel Seat Fishing Rod Components - China Reel Seat Fishing Rod Components and Reel Seat Fishing Rod Parts price
Polyurethane Arbors
Polyurethane Arbors
Reel Seat Arbors
Polyurethane is an ideal material for arboring reel seats because it is lightweight and highly sensitive - increasing feel and transferring bites
Polyurethane Arbors
Arbors for Rod Building - Free Shipping
Fuji TCH (Titanium Carbon Hybrid) Spinning Reel Seat VooDoo Rods LLC - Premier Supplier of Rod Building Components
Seaguide Carbon Fiber Reel Seat Insert