Hi! The OPS in the pic is an earlier Ursus .60. The actual .60 sized OPS are offered in long and short stroke version. there is a rear exhaust version,too. They have two piece cranckcase and gold head. the carburetor is the two needle slide type. They loos pretty close to the old Picco .60 with black head. most of the parts are interchangeable,too. The best is the short stroke rear exhaust, in my opinion.