> Allows compatibility between new ¾" (19mm) tie downs and old ½" (13mm) in-ground anchors. > Retro-fit requires removing the removable cap from older AAI® B, BX and C style anchors, or drilling out and tapping older E style anchors. 49004 ....... Retro Fit Floor Anchor - Each .......... $130 407-140 .... Retro Fit Floor Anchors - Set of Four .... $495