This is Micro Swiss aluminum heating block upgrade with slotted clamping system for CR-10 / Ender family printers and any MK7, MK8, MK9 Hotends. Threads size: M6x1.0 Block dimensions: 20mm x 20mm x 10mm Fits: CR-10-S5, CR-10-S4, CR-10S, CR-10 MINI, CR-20, CR-20 Pro, Ender 2, Ender 3, Ender 3 V2, Ender 3 Pro, Ender 3 Max, Ender 5, Ender 5 Plus, Ender 5 Pro, Ender 6, TronXY X5S, TronXY XY2 Pro, ...