Cage Type needle bearings use a roller style rolling element to reduce friction of a rotating surface. Needle Bearings have a high load carrying capacity with a very small cross section height. The needle rollers are guided parallel to the axis using a cage retainer.
The "S-" denotoes 440C Stainless Steel.
You can find schematics of the HK/SCE/TLA Series caged type needle bearings HERE.