Date: 1926. (Drawing)
The "Giant" family includes the 18J and 19J (pictured here) which are 3-valve, top action Eb basses, the 20J and 21J which are 3-valve, front action Eb basses and the 24J and 25J which are 4-valve, front action Eb basses.
What Conn said in 1926:
These "Giant" Eb basses are designed and built especially for those who are accustomed to Eb basses but who desire the sonorous volume and striking size which is commonly associated with the large BBb instruments. In volume of tone these instruments are quite the equal of any BBb basses, and yet they have a decided advantage in weight, running about eight pounds lighter than the deeper voiced instruments. There is little difference in their respective sizes, however, for the "Giant" model lacks only an inch or so of the dimensions of the "Monster".
One of the principal features of these Conn "Giant" models is the ease with which they may be blown. Like all the members of the Conn line, these instruments are constructed by means of the hydraulic expansion process, which gives an absolutely smooth sound passage, inside as well as outside, and this, coupled with the mathematical accuracy of their proportions, makes these large instruments almost unbelievably easy to play.