SEAL-LOCK FLUSH is a flush OD premium connection with metal-to-metal seal, hooked thread form and external torque shoulder for liner applications.
WEDGE-LOCK FLUSH
Hunting‘s wedge-style thread form with undercut stab and load flanks ensures industry leading performance under tension, compression, bending, and high torque loads
For more specifications:
http://www.hunting-intl.com/connection-technology#Flush