Walmart offers the Manhasset Shaft-Lock, model no. 2400, for $6.97. (Amazon charges the same with free Prime shipping; Musician's Friend has it for the same.) Opt for in-store pickup to dodge the $5.99 shipping charge. That's $5 off list and the lowest price we could find. This item locks music stands into place. It measures 4" x 2" x 2".