Hastings 2.618"/66.50 mm Bore +.25 mm Over Size, Single Cylinder Ring Set with 1.20 mm Top Ring, 1.20 mm Second Ring and a First Oil Ring is 2.50 mm.
This Hastings Single Cylinder Ring Set has a top ring manufactured from stainless steel with nitrided ring surface treatment, a second ring manufactured from grey iron with phosphate ring surface treatment. The 1st oil control ring is manufactured of nitride rail/stainless expansion with a nitrided ring surface treatment.

Application Summary:

Year Make/Model
2004-2005 Smart Cabrio
2004 Smart City-Coupe
Attributes
1st Oil Groove 2.50
1st Oil Ring Material NITRIDE RAIL/STAINLESS EXP
2nd Groove 1.20
2nd Ring Surface Treatment PHOSPHATE
Alternate Part Number 2N7434S.25
California Proposition 65 No
Engborein 2.618
Engboremetric 66.50
Hazardous Material Code N
Life Cycle Status Code Available to Order
NAFTA Preference Criterion Code B
SDR Required Flag N
Top Groove 1.20
GTIN 00075538399407