SE Bikes 6-Bolt Disc 3/8" Threaded x 142mm 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 should correspond to the type of brakes you have on the bike.
3/8" Threaded x 142mm