Aluminum and stainless steel material, all metal, uses 1.75 mm filament, compatible with Flashforge, Wanhao, and CTC 3D printers. This cooling block is compatible with PTFE coated hotends and Mini Swiss MK10 All Metal Hotend. During installation, ensure the nozzle and heat break are tightly secured at the front end to prevent melted filament from leaking through screw holes. Compatible with Wanhao i3, Wanhao i3 Plus, Monoprice Select 3D Printer v2, Monoprice Select Plus, and other similar 3D printers. Material: Aluminum + Stainless Steel. Color: Silver. The color of the silicone cover is randomly distributed and cannot be selected. Package Contents: 2 x All Metal MK10 Heating Block, 1 x MK10 Nozzle 0.4mm, 1 x Throat, 1 x Screw, 1 x Wrench, 1 x Silicone Sock. Only the listed items are included; other products are not included. Note: Lighting and display differences may cause slight variations in color. Measurement error allowance is +/- 1-3 cm.