Flexible Coupler (4mm to 4 mm) Timing Pulley GT2 (30 Teeth-10mm Inner Diameter) Min Sound output at 10

Min Sound output at 10 cm:  90 dB

This is loud siren  that can generate sound over 110 DBA

Internal Axe Diameter:             3

So if you run it from 3

SD module has various applications such as data logger

Flexible Coupler (4mm to 4 mm) Timing Pulley GT2 (30 Teeth-10mm Inner Diameter) Min Sound output at 10Connect motor shaft to anything else with a set screw coupler. These couplers are made of machined aluminum and have a spiral cut that makes them slightly flexible so they can be fit to two shafts even if they are not perfectly co linear and will help reduce bending effects. The way they are cut, create a spring effect in the X Y & Z linear axis but not in the rotational axis. That means that you will not get increased backlash so they're suitable for