Down in the candlestick portion of the mag drive is this seal that the main drive shaft slides thru. The spline on the driveshaft can tear the seal when installing or removing the shaft but you know Murphy's law if you have a spare you will never need it.
Seal is a durable Buna rubber seal that measures 1.50" x .984" x .250".
Fits all PSI Hemi mag drives single or dual.