Electra Base™ for 3/8" thick glass, solid aluminum with brushed finish, base ends are cut at 90 degrees, nylon allen set screws are located on the back side for holding the glass, shipped in plain white box. Electra Bases can also be used for holding 3/8" thick acrylic blanks. We recommend the optional Wrench/Driver (Add-ons tab) to avoid over tightening the nylon Allen Screws .NOTE: Glass length shown is actual width of the base. As this is a "thru" base, the actual glass length can be larger than the base. Recommended Glass Blanks for these bases are listed as "ADD-ONS".