The Bare Knuckle Pickups True Grit Humbucker Set is hand wound in the UK, features Alnico V magnets and is mainly aimed at hot blues, hard rock, grunge, stoner, punk and old-school metal tones. From their Boot Camp range, the True Grit pickups are in the medium output range and produce a fat, rich tone. The Bare Knuckle Boot Camp is a stripped back, no-nonsense pickup range aimed at guitar players who just want to cut to the chase and have great tone. The 50 mm pole spacing is standard for guitars with fixed bridges (e.g. Gibson Les Paul), the 53 mm spaced bridge humbucker (also called F-spaced or trembuckers) are used on guitars with tremolos (please note the 53 mm set refers to the bridge pickup pole spacing only, the neck pickup is 50 mm in both sets).