In reducing cam and groove couplings, the coupler is the first size in the part number (i.e., a 4030-DA-AL is a 4" coupler to a 3" adapter).

Couplers are supplied standard with a Buna-N gasket, other gasket types are available.
Unit of Measure
Items
Dixon Reducing Coupler x Adapter with Port

Reducing Coupler x Adapter with Port

Dixon Reducing Coupler x Adapter with Port

Reducing Coupler x Adapter with Port

Dixon Reducing Coupler x Adapter with Port

Reducing Coupler x Adapter with Port

Dixon Reducing Coupler x Adapter with Port

Reducing Coupler x Adapter with Port
Size N/A 3 x 2 in
Tap Size N/A 1/4 in N/A 3/8 in N/A 1/2 in N/A 3/4 in
Material N/A 316 Stainless Steel