The ESP Sinclair is a Floyd Rose licensed vibrato system made by ESP and used in the 1980's. The Japanese 1987 ESP Catalogue spells it as ESP Synclear Tremolo. Earlier versions lock the strings with a hex screw on the saddles and later versions uses the Floyd Rose style that raises the block from the bottom hex bolt to lock the strings. There were versions with a pop-in tremolo bar, but there were alsow versions with a bar that needed a collar. The base plate on these tremolos are rounded.