Check the listing for details. Ultimate Support TSM-138MK Mounting Bracket for Mounting Speaker Cabinets on Spe. Condition: New. Listed at 29.99 USD. Ultimate Support TSM-138MK Mounting Bracket for Mounting Speaker Cabinets on Speaker Stands - 1-3/8" What do you do if you have a speaker cabinet that does not have a built-in speaker mount socket, but you'd like to use it on top of a tripod speaker stand? Simply install a TSM-138MK to the bottom of the speaker cabinet, and you're set! The TSM-138MK is an internal, metal mounting bracket for speaker cabinets that do not have a built-in speaker mount sockets. It mounts on the bottom of a speaker cabinet (mounting inside the speaker cabinet) with included installation hardware. Item Features : Internal metal bracket securely mounts any speaker cabinet with a flat bottom. Fits 1-3/8? (35 mm) tube Diameter is 4" (102 mm) Metal fitting holds 138 lbs. (68.2 kg) Part Name: TSM-138MK Part Number: 13425 Internal metal bracket securely mounts any speaker cabinet with a flat bottom. Fits 1-3/8" (35 mm) tube Diameter is 4" (102 mm) Metal fitting holds 138 lbs. (68.2 kg) 1 year manufactures warranty ⚠️Warning: For cancer and Reproductive Harm, go to www.P65Warnings.ca.gov .