SE Bikes 12 mm Thru x 142 mm Shimano/SRAM 8/9/10; Shimano Dynasys 11 40 Hole Bicycle Rear Hubs
About SE Bikes - "In 1977, SE Racing was born with the goal of producing innovative BMX bikes for riders everywhere. Soon after, SE produced the first race ready high-end aluminum race bike, the JU-6, featuring stiff Floval tubing. This groundbreaking bike was further modified and became the legendary PK Ripper."
This is hub spacing and is the width of the hub. It must match your frame specifications.
The cassette body type is the type of cassette and number of speeds the hub will accept.
The hub drilling is the number of spoke holes. It must match your rim spoke count.