The ISC Offset Oval Keylock Carabiner combines the specification of an Oval with that of a 'D' shape carabiner.  True Ovals are not capable of achieving high breaking loads, as their symmetrical shape shares the load between the spine and the gate of the carabiner.  The weakest part of any carabiner is the gate and so wherever possible, designers will try to bias the load toward the spine of the carabiner.  This is why 'D' shape carabiners typically give the highest breaking loads.

However, in many industries such as Rope Access & Rope Rescue, the Oval is a popular shape...hence the introduction of this new hybrid Offset Oval.