BLUE -- TL42 LIQUID THREAD LOCKER. NUT GRADE PROVIDES MEDIUM STRENGTH. IT SEAL MOST NUTS AND BOLTS,USING STANDARD TOOLS TO UNTIGHTEN. LOC-TITE EQUIVALENT #242 RED -- TL71 LIQUID THREAD LOCKER. HIGH STRENGTH AND PERMANENT. FOR USE ON FASTENERS UP TO 1" IN DIAMETER. USE WHERE NO UNTIGHTENING IS REQUIRED. LOC-TITE EQUIVALENT #271