The four-gap bridge has a large and heavy copper strip of (SWG No. 18) mounted on a heavy 3/4” thick laminated base of size 45” x 4” x 3/4”. Nine heavy Brass terminals lock type are provided to reduce the resistance to a minimum. The ends gaps are closed by removable Copper Binding pieces which are held in position by the terminals. The 24 SWG constantan wire is stretched along the top of wooden meter scale and securely clamped to the Brass end strips so that end errors are negligible.Supplied complete with pencil jockey along with lead for connections. Includes detail working manual. Overall dimensions: 1.12m × 100mm × 50mm, including terminals.