Loctite-492145-545-Pneumatic-Hydraulic-Thread-Sealant-Bottle - The best for NPT / hydraulic fittings
Loctite-492145-545-Pneumatic-Hydraulic-Thread-Sealant-Bottle - Needed a high quality sealant for very small fittings, as small as 1/8 inch. This was the best I could find for NPT connections.