Up for sale is a Vintage Y.S. O.S 70, 91 etc. Surpass 4 Stroke Model Engine Silencer. I'm not positive on the size of compatible engines. This is in used condition. The threaded port is 12-13mm so the engine size may vary. Look closely at photos to see condition. I will ship as soon as payment is made. If there is a delay, I will let you know. I will combine shipping for purchasing multiple items.