Your ARC Ultimate Annealer comes with 6 guides. These are replacement guides as well as two additional larger sizes that are available for annealing parts with larger base diameters than .338 Lapua Magnum case heads. The cartridge guides come in 6 sizes with two height variations. Sizes 1 through 4 come with the ARC Annealer, including the thin versions. SizesSize 1T 0.408" ID / Thin HeightSize 1 0.408" ID / Standard Height (Small)Size 2T 0.494" ID / Thin HeightSize 2 0.494" ID / Standard Height (Standard)Size 3 0.571" ID / Standard Height (Magnum)Size 4 0.601" ID / Standard Height (Lapua Mag)Size 5 0.651" ID / Standard HeightSize 6 0.680" ID / Standard Height