These are the EWI Tourcase SP/MD subwoofer to speaker poles. The poles are sold individually and constructed with steel tubing throughout and are available in fixed or adjustable lengths.
The fixed length poles come in 4 sizes: 16", 22", 28", and 34". This is the overall length of the pole including the necked down area on each end. The fixed length poles are made from 1 1/2" steel tubing which is necked down on each end to 1 3/8" diameter for the sub and speaker cups. The necked down area is 3 1/2" inches on each end so the height of your speaker above the sub will be 7" less than the length of the speaker pole being used. For instance, the SP-28 pole will lift your mid/hi cabinet 21" above your subwoofer. ( Assuming your pole cups are 3 1/2" deep )
The adjustable MD-1 speaker pole is built with a 1 1/2" outer tube and a 1 3/8" sliding inner tube. The pole can be varied from 32 3/8" to 50 1/8" overall lengths achievable in 4" increments with 5 pin-able holes. A nylon height clutch is used to keep the speaker tube from spinning and a height pin is included and attached at the clutch knob to lock the speaker height in position. The outer 1 1/2" tube is again necked down to 1 3/8" for the subwoofer cup.
The approximate weight handling for both the fixed and adjustable stands is 60 pounds