This is a rear grip machined fit into RFBC16 Reel Seats.The inner diameter is 13mm, but The part inserted into the RBSC16 nut has an ID 20mm.
When used with the S-26ER winding check, it is natural to mount the gun grip. Please refer to the assembly example.
ID : 13mm,/0mm,OD : 26mm / Length : 90mm
ASSEMBLED EXAMPLE. GRIP KIT IS AVAILABLE.