weight plate 16 weight hooks 18 may be fixed to weight plates 16 by various means such as for example screws fig5 and 6 show a weight hook 18 detached from a weight plate 16 and in detail each weight hook 18 preferably has a downward facing hook portion 20 on each end weight hooks 18 are selectively engaged by selector hook assemblies 22 one such selector hook assembly 22 is illustrated in fig7 a and 7b selector hook assembly 22 preferably comprises a first selector hook 24 a crossbar 28 and a second selector hook 26 each selector hook 24 26 preferably has a bearing 30 passing through it where a bearing 30 is above the relevant connection with the crossbar 28 in the first selector hook 24 and below the connection with the crossbar 28 in the second selector hook 26 first selector hook 24 preferably has a selector magnet 32 fixed to its outer edge below the connection to crossbar 28 multiple selector hook assemblies 22 are preferably attached to a lift plate 34 as best shown in fig8 10 pairs of brackets 36 are preferably mounted on the lift plate 34 and have two shafts fixed between them which respectively pass through the bearings 30 on the first and second selector hooks 24 26 of each selector hook assembly 22 according to the preferred embodiment each pair of brackets 36 may support only one selector hook assembly 22 or may support multiple.