The KL321 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 KL321 Offset Oval.
ISC have now developed the process of cold forging, which allows them to offer the common Keylock style (anti-snag) noses on several Carabiners in their range, including the new KL321 Offset Oval.