The S-Board 840 Design USB Number Pad from BakkerElkhuizen is suitable for users who are intensely involved in data entry. It also acts as a handheld calculator and has an extendable USB cable.
Features
USB Numberic KeyPad
18-key numeric keypad to quickly and efficiently enter long sequences of numbers
Plug and Play via 5 ft/150 cm USB cable (No software required)
Thin (only 0.5"), compact and white to match perfectly with Mac
Flip-out cable manager bracket
System requirements: USB port; Mac OS X v10.6 or later; Windows 7/8/10