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, but it is tapered to accommodate a wide range of tips. ◇ If adjustment is needed, please use aluminum foil, etc. (See photo 4). ◆ If you purchase multiple sets, we will discount the shipping cost, so please comment in advance.