Its the legendary Thomson Masterpiece seatpost, in a 16mm setback design for riders/frames that need offset toward the rear of the bike. Please note: Thomson does not recommend the use of shims on their seatposts. Same proven, reliable and easy to adjust 2 bolt head 100% made in the USA The Masterpiece model offers additional machining for weight savings claimed 199 grams | Thomson | Masterpiece Setback Seatpost | Black | 31. 6 X 350Mm | Aluminum