Aluminum is significantly lighter than steel and is therefore far more popular in the outdoor and climbing industries where weight is a major factor.
Non-locking gate for general use and when clipping quickly is important. All non-locking carabiners are spring-loaded to ensure immediate gate closure upon release.
Straight gate is the most common gate used. It tends to be a bit stronger than bent gate carabiners.
Keynose carabiner does not have a notch to snag onto anything. Making clipping/unclipping simple.
Oval Shape this symmetrical shape keeps the load from shifting, creating more stability.