The rockO Screw-Lock is a blend of the traditional oval and the rockD giving it more strength than the standard oval. This design is great for users that need extra room at the bottom of the carabiner while keeping their gear aligned.Two important features make the Rock Exotica Screw-lock unique from all others. First, all aluminum parts are anodized. This is particularly important for the screw-sleeve and gate, since without this coating, it is more susceptible to corrosion. This protective surface also gives the sleeve a smoother spin.Second, the gate was designed with an enlarged flange at the top. This prevents the screw-sleeve from moving past the end of the gate, whereas with other designs, the sleeve can wear past the last thread of the gate and slip off.