503 Rotax aircraft engine , 117 total hours since new , no damage never been apart has 2:58 (B) gearbox that can be mounted as engine can right side up or upside down has electric start and pull start also Single carb , no muffler is included because there is four type available for these engines so the price reflects the price of being without a muffler which will be up to buyer to buy one of choice . comes with all in the picture and free shipping is at the buy it now price only