The head can be removed, but I don't know if there's no connector or if the integrated plate is broken. Please use it by direct adhesion. The tip of the head is about 10.5-10.8mm. The tip of the main body is about 10mm with a depth of about 8mm. The back is 8mm with a depth of about 10mm. The inner diameter changes around the vertical arrow in image 5. The grip is not glued, so you can pull it out and set your favorite one. It is a very old item, and there is deterioration over time, but there is no problem with use. For those who understand old, vintage, and used items. For those who can proceed with the transaction smoothly. Only those who understand Japanese, please. Topwater Champion Grip Old Rod Rod Building