These are #2 All Threads from Ohio Superstar.
FEATURES: Black plastic construction.
More universal than the old brass fast threads because any screw
will work (machine screw, metal screws, etc).
Can be used with any material that CA glues will bond with (woods,
Perfect for hatches, cowls, canopies, engines, landing gears, servos,
wings (anything that mounts with a machine or metal screw).
INCLUDES: (8) #2 All Threads
BOX DIMENSIONS: 2.13" W. X .13" H. X 2.25" L.
BOX WEIGHT: .01 LBS.