Umarex airgun cleaning kit -- strange parts

I just bought an Umarex airgun cleaning kit for my airguns. IMHO it's an odd collection of gadgets. There is a plastic handle that accepts the flexible cleaning rod and the included screwdriver bits, but the other end has a female brass threaded insert that fits nothing in the kit. Also, there is a small round plastic piece that also fits the flexible cleaning rod, but if the plastic handle fits, why is this piece included?

I would appreciate any answers explaining these two issues . Thanks.