said coil 18 a seat 19 electrically neutral with an axial opening 20 for the horizontally movable shaft 5 to slide through the seat is placed transversely and has a vertical opening 6 for the passage of the rod 1 an intermediate vertical slot 8 for guiding the portion of the rod 1 above the seat 19 and coaxial to the opening 6 a lower vertical slot 9 for guiding the portion of the rod 1 below the seat 19 and coaxial to the opening 6 a block 11 which can be moved up and down where the removable seat 19 is fastened and where slots 8 and 9 are provided the block is also provide with a wall 12 on its top for closing its upper part a fixed shield 14 with an opening 15 for the passage of the rod 1 coaxial to slots 8 and 9 the shield being mounted below the ring 2 and the opening 15 being provided with a border 16 for the protection and support of the ring 2 the arrangement of this alternative permits through the interaction of the movements of the shaft 5 and of the block 11 of each of its functional units the selection of rods 1 which are to be moved upwards or downwards at each cycle of the equipment according to the effect desired in the resulting fabric in this system you can choose whether or not the rod 1 will be moved upwards or downwards in coordination with the block 11 with the resulting movement of the warp thread f carried by each of the rods forming the entire functional unit at issue the text below describes a functional unit based.