The T-H Marine Transom Support / Washer Plate is made of strong 3/8" 6061 T6 alloy aluminum (not cast aluminum). The CMC transom washer can eliminate bolts "biting" into transoms and can more evenly distribute loads on high-performance engines.• Constructed of strong 3/8" 6061 T6 alloy aluminum• Eliminates bolts "biting" into transoms• Evenly distribute loads on high performance engines• Dimensions: 12" x 2"• Mounting Holes on Center: 10" More evenly distributes loads on high-performance engines Measures 12" x 2" with 10" holes on center | and CMC Machined Transom Support Plate, Lower Bolt Holes, Standard