METAL STEM & Screw thro bowl
The Bon Aire was from the Waldorf Pipe Co., 519 W. Randolph Street, Chicago Illinois. The device on top of shank is a smoke flow control
The bowls seem to be classed as extra large or medium size. I have 15/16 chamber diameter and depth Mandarin shape and Apple, and also 13/16 diameter chamber with depth of 3/4 inch in those 2 shapes and there are rusticated versions.
I have two examples, one with a round end cap that screws in (shown here), and another with a square ended cap that is a push fit. This one actually is stamped on underside near stem BONAIRE PAT 116494 OTHER PATS PEND. This patent was issued to Jack Galter of Chicago 5 Sept 1939. Jack Galter also patented a cigarette lighter very similar to Zippo in 1945 This one also has a push fit smoke control, seemingly not too good an idea as pliers seem to be the only way to turn it if an air tight seal is made.
The pipes appear to have been sold in a set with three bowls, and bowls were also supplied in sets of three for $1.00 incl shipping !!!
Additionally there are two distinctly different sizes, The Junior is 5 inches long overall and sides 7/16 inch wide at the widest part and the larger Senior at 5 3/16 inches overall and sides 5/8 inch wide at widest point