APM2.6 Flight Controller Board with Top-Pin Connector for ArduPilot Mega 2.6 Flight Control Board : Amazon.sg: Toys
Flight Controller Side Pin APM 2.8 Board For Multicopter ARDUPILOT 2.5/2.6/2.8 | eBay
Amazon.com: FPVDrone 3DR 500MW Radio Telemetry Kit 915Mhz Air and Ground Data Transmit Module for APM 2.6 APM 2.8 Pixhawk Flight Controller : Toys & Games
Archived:APM 2.5 and 2.6 Overview — Copter documentation