As per actual items in images . Haro Fusion mid school 1990s BMX seatpost double clamp . Items are new from 1990s. Kindly see specs for sizing/ clamp diameyer applications.
Haro Fusion double seatpost clamp - black
****Bottom Frame seat tube mount diameter 25.4mm/ top bolt mount for seatpost/ seat pillar 22.2mm
This will work with frames using older regular seatpost size (22.2mm) . One bottom bolt secure clamp to seat tube for normal fastening/ one bolt top bolt to secure seatpost only. Price 45 each.
Do pm to deal if keen thanks!