There is only 1 titanium model now: the Charge TTi with an s30v blade. It is top of the Leatherman line. The AL and ALx are the Aluminum versions with lessor (but still premium) blades of 154cm. There was originally (now retired) other versions like the XTi etc. Anyway, the AL and ALx are a slightly less expensive option. So the current Charges are TTi, AL, and ALx. One of the ALs has scissors, the other not. Hope that helps