Gehrke&';s XinkA(R) Gehrke&';s XinkA(R) is one of the most revolutionary inventions in fly fishing since the discovery of the hook. The product can eliminate the majority of the lead used in nymphs and wet fly patterns throughout the world if everyone started using it. It is wetter than water without washing off, which seemed impossible until George Gehrke&&';;s invention. Gehrke&&';;s XINKA(R) is the only patented fly sink in the world and has been in the market for more than 35 years .5 oz.