Dyna-Sonics had COB (chrome over brass) shells. Only a small number of wood-shell Dyna-Sonics was made during the lifetime of the drum. Pristine models can fetch thousands of dollars on the vintage drum market. Other notable Rogers drums were the Powertone model of snare drums and the Holiday model of tom-toms and bass drums. Fiberglass timpani were also manufactured for a time, named Accu-Sonic. In addition to its Dyna-Sonic snare drum, Rogers was renowned for its highly-innovative hardware. Much of it was developed by Thompson, including the Swiv-o-Matic line of bass drum pedals, hi-hats, cymbal stands, and tom-tom holders. The cymbal stands and tom-tom holders featured a ball-and-socket tilting mechanism. Even Ludwig drummers like Ringo Starr of The Beatles, Mitch Mitchell of The Jimi Hendrix Experience, and John Bonham of Led Zeppelin used some Swiv-o-Matic hardware items on their kits. Keith Moon used Swiv-o-Matic hardware on his Premier kit. Neil Peart of RUSH played a Rogers 5"x14" Rogers Dynasonic Snare on Fly by Night, Caress of Steel, 2112 and All The World's A Stage. He also used Rogers hardware, specifically, a single Swiv-o-Matic tom holder on his large Slingerland and Tama drum kits through the mid-1980s in order to position a tom-tom directly over the center of one of his bass drums. From 1964 until 1975, Rogers shells were 5-ply construction of alternating plies of maple and birch wood with reinforcement rings. From late 1975 until 1978 the shells were made up of 5 alternating plies of maple and birch wood with reinforcement rings. Starting in 1978, Rogers began offering drums with 8-ply shells without reinforcement rings (made by Keller Products, Inc. of Manchester, NH) for its XP-8 line. They marked the beginning of relatively heavy, thick "stadium" shells that favored attack and projection over midrange tonality. These drums were promoted as "the best Rogers drums ever made" and the XP-8 models lived up to that claim. 1976 saw the introduction of "Memriloc" hardware. This innovation was co-developed by Dave Donoho and Roy Burns. It was the first of the super-stable hardware systems and was subsequently copied by most major drum manufacturers in one form or another. Most modern drum hardware evolved from the Rogers Memrilock concept. For the growing European market, Rogers drums were made in the UK by Ajax under license from Rogers USA. The hardware was Rogers, but the drum shells were supplied by Ajax from its