Cover Reac 3neck O-Ring ,Each

Details:

Reaction vessel lid, flat flange, o-ring seal, 3-neck^ flange diameter: 6-5/8"; o-ring size: 359; center neck: [st] 29/42; side necks: [st] 29/42. Grooved to accept an o-ring and creat a greaseless, vacuum tight seal. Supplied with center neck and two side necks that are 180[degrees] apart.