tell me what these 2 feet are ??? please

both are side screw on feet


one is plastic with a square hole in the middle and a pencil led size space ( slit) in the front ??

the second foot is rectangle , with a rectangle hole in the middle, the front of the foot is slanted upwards with a screw on top holding a straight skinny black piece of metal that runs straight to the back of the inside rectangle ??

any ideas ?

i've looked and looked and can't find these 2 pieces on the net.

thanks for any help you can give..

miss daisy