PRS Guitars (also known as Paul Reed Smith Guitars) is an American guitar manufacturer headquartered in Stevensville, Maryland, founded by luthier Paul Reed Smith in 1985.
Music Man is an American guitar and bass guitar manufacturer.
 It is a division of the Ernie Ball corporation.
Diamond Guitars is an American guitar manufacturer owned and operated by Jeff Diamant of Diamond Amplification, along with partner Terry Martin.
 Former Dean Guitars founder and owner Dean Zelinsky was a co-owner from 2008 until his departure in 2012.
 He left the company to form his current brand, Dean Zelinsky Private Label.
Rian Adkinson (born 22 March 1980) is a singer-songwriter/multi-instrumentalist from Atlanta, Georgia.
 During his career, Adkinson has been featured in Prog Magazine, Billboard Magazine, Free Times Columbia, Creative Loafing, Stomp and Stammer and more.
 Adkinson is a PRS endorsed artist and is known for using the S2 Mira Antique White and the S2 Custom 22 SH.
C.F. Martin & Company is an American guitar manufacturer established in 1833 by Christian Frederick Martin.
 Martin is highly regarded for its steel-string guitars and is a leading manufacturer of flat top guitars. Martin instruments can sell for thousands of dollars, and vintage instruments occasionally command six-figure prices.
 The company has also made mandolins as well as several models of electric guitars and electric basses, although none of these other instruments are currently in production.
Hallmark Guitars is an American guitar manufacturer.
 The company was founded in 1966 by Joe Hall, formerly of Mosrite.
"The Deceiver" is a limited edition guitar made by the American guitar manufacturer B.C. Rich.
 Based on their 'assassin' guitar, The Deceiver was only made during March 2003 as part of the Body Art Collection.
 The image on the front of the guitar is of several snakes copyrighted to "Skate the Planet".
Taylor Guitars is an American guitar manufacturer based in El Cajon, California and is the #1 manufacturer of acoustic guitars in the United States.
 They specialize in acoustic guitars and semi-hollow electric guitars.
 The company was founded in 1974 by Bob Taylor and Kurt Listug.
The American Guitar Academy was founded in The United States in 1991.
 It opened its first international location in Tokyo, Japan in 2011.
 It claimed to be the only guitar school in Japan offering classes in multiple languages including Japanese, English, Spanish, French, Italian, and German.
 American Guitar Academy teaches all styles of acoustic and electric guitar from Jazz, Rock, Blues, Pop, Funk, Classical, Flamenco, Tango, Folk and R&B and more.
ES Guitars is an American guitar manufacturer of electric guitars and bass guitars.
 Established in 2003, the company manufactures guitars in Connecticut but the main office is located in New York.
 The company focuses on Heavy Metal and Hard Rock guitars.

Question: What is the American guitar manufacturer headquartered in Maryland founded in 1985 that endorsed Rian Adkinson?
Answer: PRS Guitars