This is a 40mm aluminum extension adapter. It is lightweight and durable. It is compatible with standard 5mm base diameter fishing rod tips (Shimano, Daiwa, etc.). The thicker pipe is 30mm long, the thinner pipe is 40mm long, the overlapping section is 10mm, the total length is 60mm, and the weight is approximately 1.4g. Since it is handmade, there may be slight variations. ★ Even with the same 5mm base diameter, there may be slight differences in thickness depending on the manufacturer. If adjustment is necessary, please use aluminum foil, etc. (The holes are made slightly wider and the shaft slightly thinner to make adjustments easier.) ◆ If you purchase multiple sets, we will discount the shipping cost, so please comment in advance.