Hastings, 107" M8 chrome piston ring set. +.020"

Standard cylinder bore: 3.937" (100mm) bore.
1st. ring: 1.2mm.
2nd ring: 1.2mm
Oil ring: 2.0mm
Stock replacement for 107" models. Comes with a chrome top ring, a ductile iron Napier 2nd. ring and a chrome flex-vent 3-piece oil ring.

Tech tip: Piston grooves vs piston rings.
It's not difficult to determine if a Hastings piston ring set will fit a certain piston. You should measure the height of the piston groove in the piston itself. The 2 top grooves will be for compression rings, the lower groove will be for the oil ring. In most cases Hastings oil rings are of the low tension 3-piece flex vent type. Ring heights are listed for reference.
Tech tip: Piston oversizes.
For each oversize cylinder diameter will increase with .010" (0.254mm). The standard bore of the cylinder is listed for reference.
(Information provided by Hastings Manufacturing Company, Inc.)