This is a major repair kit for the Fisher Scientific M12C and Welch 8920 (old style/1st generation) two-stage rotary vane pumps. This kit includes GX vanes and all other parts necessary for a major overhaul of the pump including: O-rings, gaskets, seals, key, valves, springs, and other components.

Note: The external appearance of the pump is not 100% accurate in determining whether you have an old style or a new style pump. The only way to accurately verify the style of pump is to disassemble it to determine if the pump has a one or two piece rotor. First generation (old style) pumps have a 2 part rotor. Please see the exploded pump diagram in the second image.