Metal Keyboard with Trackball(IP65 NEMA 4X); Trackball Diameter:38mm; Key travel: 2.50mm; 65 Customizable 316#(RoHS) stainless steel keys; Supply Voltage: +5V DC +/-5%; Lettering: Sunk laser legends & characters in high quality ink; Actuator/keys materials: 316#(RoHS) stainless steel; Switch life: more than 3 million of operations; Compatible with WindowsNT, Win98, Win2000, WinXP Interface: PS2, RS232, USB available; Lifespan: > 5 years; CE, RoHS, FCC IP Protection Class IEC/DIN/EN/ 60529:IP65 IK Protection Class DIN EN 50102:IK07 GW: 2.10KGs.