No. 45 steel is a kind of iron, which is harder and stronger than ordinary iron. Very durable. The coupling is an accessory that connects the motor shaft and the optical axis, as well as an accessory that connects the two shafts. Screws are not included.
4mm to 4mm means: one end has an aperture of 4mm, and the other end has an aperture of 4mm.
[Product Length]: 22mm
[Product Diameter]: 6-10, 8-10, 10-10 three specifications are 16mm, other specifications are 14mm in diameter
[Product Specifications]: 4-4, 5-5, 5-6, 5-8, 6-6, 6-8, 6-10, 8-8, 8-10, 10-10
[Product Material]: 45 # steel
[Product weight]: about 20 grams
[Hexagonal small package]: In order to facilitate customers who do not have an hexagonal wrench, a hexagonal small package (wrench + screw) is specially introduced, which includes: 1.5mm wrench, 2mm wrench, 3 * 4 machine-meter screws 5, 4 * 4 machine screws 5 pcs