BRX Masters with 6-ply, 7.5mm birch shells was introduced. In 2003, Masters RetroSpec MSX, with 6-ply, 7.5mm maple shells in a retro-style Delmar covering was introduced and ran until the beginning of 2007. In 2006, Masters Studio BSX 6 ply birch "glass", with 6 ply, 7.5mm birch shells, in a Delmar glass covering imbedded with real glass flakes was introduced. In 2007, Masters series was simplified into two lines: Masters MCX and Masters Premium. The first Masters kits from 1993 had 1.6mm steel hoops, the same as Export. In 1994, they were switched to 2mm steel (gold plated) and 2mm stainless steel. In 1996, they were switched to 2mm steel. In 1997, they were switched to 2.3mm SuperHoop II's. In 1999, they were switched to die cast. Most of their finishes are now available on their Masters Premium and Reference series drums. MX, MLX & BLX - The predecessor of the original Masters series, with the MX being a wrapped 6ply (7.5mm) maple kit, and the MLX and BLX being lacquered 6ply (7.5mm) Maple and Birch Kits respectively. Included 2.3mm Superhoops, through-shell mounting and often came with a free-floating snare. GLX - This kit was the high end of Pearl during from 85 to 88. Made with maple, the Pearl Prestige Artist 9500 a.k.a. GLX shared the same specs as MLX except it also included a very unique lugs system called "Super Gripper". They were a notched release type lug casing, loosen the rod a bit and the casing pops off the release the nut so the rods don't leave the rims. DX & DLX - Introduced in 1984, they were professional line of drums, placed just below MLX and BLX series, and featured high-end components such as double braced hardware and SuperHoops. DX (Studio 7300) were available in a wrapped finish, and the DLX (Prestige Studio 7500) were available in a lacquered finish. Shells were 7-ply: 1 ply birch, 5 alternating plies of mahogany and lamin wood and 1 ply birch. This series were made in Japan. In 1987, the DX/DLX were discontinued and replaced by the WX/WLX. From 1997 to 1998, the DX Session (covered finishes) and DLX Prestige Session (lacquer finishes) made a brief “comeback” and featured 7 ply, 7.5mm shells constructed of maple (inside), mahogany (middle) and maple (inside). Prestige Session and Session featured the same shell construction as Pearl Session Select (SRX), but SRX came