The 4.5 mm Serial Guide Sleeve (SGS 4.5) is used with serial guide sleeve inserts ranging from 2.0 mm to 4.0 mm (see Guide Sleeve Inserts). Measure the drill diameter before ordering inserts; inserts should be slightly larger than the drill size. All inserts are press-fit and require the Insert Removal Tool (IRT), the Fabrication Insert (FABIN 4.5), and the 3.0 mm Guide Post.