This is a replacement Synthesis Rotor bottom half for the Biolytic 3900 and the Dr. Oligo 48. We have redesigned this to use O-Ring seals around the banks in place of the original flat gasket therefore the flat gasket is no longer used with this rotor bottom. This rotor bottom assembly includes 5 each check valves on the bottom, 4 each O-ring seals for the banks, one each priming pipe. 

A pack of 4 spare O-rings for the bank seal may be purchased using PN: 381-103076-4

This rotor base design incorporates a larger volume space for each bank below the columns (Bank Trough). This design was adapted to allow this to be used for the Biolytic 3900 and the Dr. Oligo 48. However the ABI 3900, the MerMade 48 and the Northwest instruments should not have this larger volume below the columns.  To use this rotor base for all these instruments  you will need to purchase 4 each inserts that fits in the rotor base below the columns. One insert is needed for each bank in a rotor (one rotor needs 4 each bank inserts)
The bank inserts are Part Number: 263-106265.
This Synthesis Rotor Base Assembly does not include bank trough spacers because the bank trough spacers are not used  the Biolytic 3900 or the Dr. Oligo 48.