Package Contains:1xGRBL 1.1f 3 Axis Control Board V3.4+ 1xUSB cable+1xOffline Controller+1x1G SD card, 1xSD card cover, 1xconnecting cable, 1xinstructionsBasic Parameters: USB (USB-CH340), Input voltage: 12-24V,masterchip atmel 328P (for Nano),spindle drive chip MOSFET (recommendation 24V, current within 10A), Current interface: DC, 5.5-2.5 mm (please confirm, the indicator lamp on the control panel lights up when the installation is complete)Improved spindle drive (support spindle with 20000rpm), Improved USB connection added offline detection, can insert offline modules and computers at the time, also automatically detects whether computer control is available isSupported Software GRBL / Candle (3 axes) / Universal Gcode transmitter, system Windows XP/7/8, Nema 17/23 (42/57);Offline Control support SD card and tf card at the time, standard capacity 1G, (notebooks generally have SD card interface, copy files are very convenient)Connection: USB (USB-CH340)Software: GRBL-Controller (Candle)Laser-grblInput voltage: 12-24 VMaster chip: Atmel 328P Driver: DRV8255Spindle driver chip: MOSFET(recommendation 12-24 V; current: within 10 A); Spindle PWM speed: support;Laser engraving: support; interface: 5.5-2.5mm DC interfaceColour:As shownMaterial:Metal + PlasticPackage Contents:1 set x grbl controller1 x English manualOnly the above package content, other products are not included.Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.