Used laptops.

Core i5 (2nd Generation)
2.5 GHz
RAM : 4 GB
Hard Disk Capacity : 500 GB

Intel Core i5
4 GB DDR3 RAM
128 GB SSD
Mac OS

Wi-Fi + 3G

Size and Weight:
Height: 9.50 inches (241.2 mm)
Width: 7.31 inches (185.7 mm)
Depth: 0.34 inch (8.8 mm)
Weight: 1.35 pounds (613 g)
(Wi-Fi + 3G model)
Weight: 1.34 pounds (607 g)

Storage:
16GB

Wireless and Cellular:
Wi-Fi
Wi-Fi (802.11a/b/g/n)
Bluetooth 2.1 + EDR technology

Wi-Fi + 3G:
Wi-Fi + 3G model: UMTS/HSDPA/HSUPA (850, 900, 1900, 2100 MHz); GSM/EDGE (850, 900, 1800, 1900 MHz)
Wi-Fi + 3G for Verizon model: CDMA EV-DO Rev. A (800, 1900 MHz)
Data only3
Wi-Fi (802.11a/b/g/n)
Bluetooth 2.1 + EDR technology

Display:
9.7-inch (diagonal) LED-backlit glossy widescreen Multi-Touch display with IPS technology
1024-by-768-pixel resolution at 132 pixels per inch (ppi)
Fingerprint-resistant oleophobic coating
Support for display of multiple languages and characters simultaneously.

Chip:
1GHz dual-core Apple A5 custom-designed, high-performance, low-power system-on-a-chip

Cameras, Photos, and Video Recording :
Back camera: Video recording, HD (720p) up to 30 frames per second with audio; still camera with 5x digital zoom
Front camera: Video recording, VGA up to 30 frames per second with audio; VGA-quality still camera
Tap to control exposure for video or stills
Photo and video geotagging over Wi-Fi

External Buttons and Connectors:

Input/Output
Wi-Fi:
30-pin dock connector port
3.5-mm stereo headphone minijack
Built-in speaker
Microphone

Wi-Fi + 3G:
30-pin dock connector port
3.5-mm stereo headphone minijack
Built-in speaker
Micro-SIM card tray (Wi-Fi + 3G model)
Microphone

Sensors:
Accelerometer
Ambient light sensor
Gyroscope