This is a pair of 1/4x3/8" Ceramic Nitride Pro Series Bearings|
from Acer Racing.
Diamond polished Ceramic Nitride Balls for low friction, low heat
build-up and smooth operation
Sealed with exclusive no contact seals for low friction and super
Lightly oiled with a exclusive SIN synthetic oil in a special
process that creates an ionic bond for silky, frictionless action
New HSR bearing cage design is specifically engineered for high speed
and high stress RC racing applications
Two 1/4x3/8" Ceramic Nitride Pro Series Ball Bearings
Inside Diameter: 1/4"
Outside Diameter: 3/8"