Many player don't have much free time to do maintenance, and we got many request to make free maintenance parts, especially for the Actuator.
Golden bearing as an actuator can minimize radial friction, but the axial friction to the switch hinge/blade can't be avoided. When using Metal Actuator including Golden Bearing it need small amount lubrication on the actuator outer diameter to reduce the friction against switch blade.
So we decide to make bearing actuator with using plastic sleeve. We choose to use POM plastic, it have low friction and perfect for free maintenance applications. Installation is the same as Golden Bearing, it need installed between Bushing and ring, but on Black Bearing it is easier since both face (top and button) have the same profile and doesn't need specific orientation to make correct installation.
Compare to metal, plastic is softer material and can wear out quicker than metal. please check regularly if the wear out is too much, consider to replace it to keep the lever performance optimal. You can also put small amount silicone lubricant to the outer diameter to reduce friction (oil based lubricant is not recommended since it can damage plastic in long period).