- Black spring - Clear body - 46mm diameter piston - S: Single tube - D: Monotube high pressure gas type of shock absorber with internal reservoir in the main body - R1: Adjustable rebound damping shock. Adjuster wheel above the end eye - Length: 341.5 mm - Stroke: 57.5 mm - Spring 21103-36 - Rate N/mm: 105 N/mm Öhlins STX46 Custom & Heritage rear shock absorber offers a classic timeless look with advanced technology. The STX46 is a monotube high pressure gas type shock absorber 46mm piston diameter with a internal reservoir. Complete with installation instructions. Note: Approved. Check your local MCS dealer or the MCS sales department for exact type of approval and validity on bike model and years on the test report.