Cheap batches 10 batches until gone, LUCAS ALTETTE  DOMES CLASSED HERE AS 2nd GRADE HENCE LOW PRICE. Integral threaded legs = 4 x 1BA & 2 x 1/4" BSF.

NORMALLY AS USED ONLY WITH RIPPLED STEEL DISC ON CAST IRON HF 1234 or  HF1235  LUCAS HORNS, THESE DOMES ARE REGARDED as 2nd Grade Quality to us & come with 2 spring washers. Perfectly usable.