The ring

 

When you purchase a Seymour Duncan Trembucker pickup, a complementary mounting ring will be included - have you ever wondered why?

Before we begin, Trembucker here refers to the slightly wider pickup pole pieces of the Seymour Duncan bridge humbucker to accommodate a Fender-spaced string spacing type. This is usually in the range of 5cm - 5.2cm. The DiMarzio version of this string spacing is called the F-Space. Contrary to popular belief, F is not for Floyd Rose, it's for Fender. The Floyd Rose brand follows the Fender spacing. Logic would tell us that, chronogocally, the Fender bridge was created way before the Floyd Rose.

Moving on, unlike other pickup manufacturers, Seymour Duncan actually widens the pickup structure to match this spacing. Other manufacturers simply space out the pole pieces only, the pickup dimensions remain the same. This is the reason why the SD Trembucker is a super tight fit in many default pickguards & mounting rings as those do not accommodate the Trembucker. This is the reason why SD includes a mounting ring when you purchase a Trembucker. From the picture above, we note that SD mounting ring (top) is slightly wider than the Ibanez mounting ring (bottom) which was chosen for this example.