Relief 3 are characterized by their larger size and have three cap bands. Nibs are the larger #3 size. This model was offered in five colors (BHR, BCHR, Lapis Blue, Inlaid Green, and Pearl Red.  Available in 3-L (Lever filler) and 3-S ("Stud" filler). Most common in black hard rubber variants.

This is a black hard rubber model 3-S button filler with a broad nib and a more unusual model 3-S in lapis blue.

Relief 4 are characterized by being the largest size in the Relief lineup and are approximately the same size as a Parker Sr. Duofold.  They also sport huge #4 nibs and have a three cap band configuration of thin, thick, and thin. Offered in two colors, Black Hard Rubber with Lever filling (4-L) and Mottled Blue with Stud Filling (4-S).  Model 4 pens are quite rare today.

A model 4-L in Black Hard Rubber

Relief 5 are characterized by their slender size and twin cap bands.  Due to their slender size, they are only offered in the model 5-L (Lever filler) version.  Typically advertised as being in only three colors, examples can be found in black, reversed cracked ice, marbled green, and blue and copper marble.

Two 5-L's, including the highly desirable blue and copper marble variant.

This is a Relief 22-L which is a smaller sized version of the 2-L.  These came with or without clips.  Clipless models had ringtops, and there was even a version with both a clip and a ringtop.  Models can be found with or without a single cap band, just like the model 2's.  Unfortunately, this example has a burn problem at the end of the barrel.

Relief 12 are characterized by their resemblance to the Conway Stewart model 28 and were made durng the 1950's.  They were available in patterns not found on previous models, including the cracked ice, tiger's eye, and hatched patterns as seen below.  Model 12 all have #2 nibs and have the same style lever as seen on model 2 pens.

These are Relief model 12's.