Our take: This replacement head w/ spoon is designed as a back-up or replacement for your Thunder B's original head. As you can imagine, after many times of use, your Thunder B head may be worn/damaged beyond additional use.
Now these replacement heads are available so you can purchase them individually and not have to purchase a brand new set of Thunder B's just to get the head replaced.
Construction: Chamber made from machined Aluminum, Head made from nylon fiber
Package Includes: 1 Thunder B Factory-Spec Grenade Core w/ Head & Spoon, 2x Replacement Grenade pins