These Thumb Locking Over centre latches throw a 6:1 Closing leverage, making it far easier to lock down latches than the standard Eezi Awn Stealth RTT.  (Which comes stock with a 1:1). 
Thumb locks add to secuity of the latch, while these type were specifically chosen as they match the majority of the existing latches rivett holes, minimising effort to make the upgrade.