Zink ZNK-ZNK6043 NBG Duck Call Poly Single, GunsmokeCreating Waterfowl Calls from Zink requires special attention and most premium materials. Mouthpieces and bells are machined using software that considers every millimeter of every cut. Each call will ultimately run through the lathe three times and the mill once. With the cuts perfected, calls are hand buffed or flame polished for that gorgeous Zink finish. Our waterfowl expert secures the reeds and guts and then places the finished pieces together.