Gasket Retainer with spikes, Straight for front and rear. These are used on the Dr. Oligo synthesizers 96 - 768. These use 6-32 screws. These are wider than the original gasket retainers. These can be used to replace the original straight gasket retainers however you will need 6-32 screws and you will need to drill out the existing 4-40 hoes and tap them to 6-32 holes. You will also need the new type curved gasket retainers if you want to fully upgrade to the new type gasket retainers. The curved gasket retainers with this same design are PN: 262-104369. The advantages of these new type gasket retainers is that they hold the gasket in better and they make a better seal without need for silicon sealer when installing them.