This auction is for a  pair of vintage yamaha snowmobile head and base gaskets, one of each. These are NOS parts, the part number for these is 811-11181-00 for the head gasket and 811-11351-00 for the base gasket.

Looked these up on the Yamaha web site and found that these will fit the 1970 SW 396 and the 1971 GP 396 snowmobiles.

If there are any questions about this item, feel free to email me. Thanks