The F Type coupling consists of two flex hubs, two sleeves (with O-Rings) and one accessory kit. Exposed bolts (E) are the standard design for this coupling, though shrouded bolt (S) designs are available upon request through size 5.5. The F Type has a max angular misalignment of 3.0 degrees (1.5 degrees per gear mesh). Lovejoy® Gear Coupling O-Ring, -40 to 212 °F, Buna-N 70, Black