This Blue Fireball adapter has an SCT male thread (2"x24TPI) as well as a 2" filter female thread (M48x0.75) on one side. It has a T / T2 male thread (M42x0.75) on the other side. So this adapter can be used as (i) an SCT male to T / T2 male adapter, or as (ii) an M48 female to T / T2 male adapter.
However, please note that you can use EITHER the SCT male thread on one side OR the M48 female thread on the same side. You cannot use both threads simultaneously, for example, to attach a 2” filter in an SCT chain. It will simply not work since the outside diameter of a 2" filter cell is exactly the same size as the SCT thread. If you attach a 2" filter to this adapter, the SCT male thread is no longer accessible/usable.
Total thickness = 9.5mm (0.37"); length of male T thread = 3mm (0.12"); length of male SCT thread = 3.5mm (0.14"); length of female M48 thread = 2.2mm (0.09"); maximum outside diameter = 52mm (2.05"). Made of black anodized aluminum.Blue Fireball part number: T-07