Version 1, 2 and Glide Tech MirageDrive sprockets. V1 is the earlier version of MirageDrive sprocket, employing grub screw to lock the mast in place. The Glide Tech sprocket uses a threaded brass insert that the fin masts screw into 

• V1 - Part# 81128001 (For old style sprockets that secure masts with set screws)
• V2 - Part# 81129001 - *No Longer Available - Order Glide Tech version for V2 drives
• Glide Tech - Part# 81127001 
• Sprockets sold individually