This is a class case for the 4/4s.
It has slightly longer hole cutouts for the volume and silence buttons on the left - This means that it will fit the 4 and 4s. The 4s's buttons are slightly lower.
Its pretty thin on the phone and feels very sturdy. The back material feels slightly like soft leather. The surrounds feel smooth and not tacky, yet grippy at the same time.
It looks fab with the white 4s due to the white on black contrast.
Good, sturdy, not cheap and nasty (most importantly!!).