Gibraltar Hinged Memory Lock 12.7Mm

I bought this for my cymbal boom stands. I have the single adjustment style boom arm, and rather then upgrade the stand, I picked up these locks to help keep the cymbal from flopping if the screw gets loose. The adjustment teeth keep the cymbal from falling forward when the screw gets loose from play, but without this memory lock, the cymbal can spin upside down when loose. Frustrating when this happens on stage. Well the locks work well, if the screw gets a little loose the cymbal only tilts a little until it engages the lock tab, and does not spin upside down. When I see the angle change a little, I know to adjust and tighten the screw before the next song. This design is nice in that it uses a nut so you can switch the side the key goes in, but be careful on stage if you use the hinge feature to place on your stand. There is a spring that flies out when you open it, and the nut falls and gets lost easily. Still I like the abilty to switch threaded sides, as the 10.5mm version is only threaded on one side, and if that is the wrong side for you, then you are stuck.