A good quality molded nylon mount. I had previously purchased this one ... Adjustable Engine Mounts (Large: 20-48 Size) PRODUCT ID: OR004-00504 ... at a higher price and to be honest, I can really see no major differences in quality and the accommodated engine crankcase sizes between either one. Like the other engine mount ( PRODUCT ID: OR004-00504 ), this engine mount will accommodate engine crankcase sizes from 28mm ( 1.10 inch ) to 35mm ( 1.38 inch ). This mount includes 4 bolts and 4 lock washers. The bolts are 3.5mm x 25mm. No nuts are included and you will need 4 nuts ( or blind nuts ) which are 3.5mm size if you will use nuts. Luckily I did have 4 nuts of the 3.5mm size on hand and they fit the bolts exactly.