Amazon.com: Replace for Ryobi 40V Battery 6.0Ah, for Ryobi 40V Battery OP4060, Replace for Ryobi OP4040 40v Battery OP4060 OP4050 OP4040 OP4015 OP4026 OP4030, Fit All Ryobi 40V HP Series Tools :
40V Attachment Capable Power Head Kit - RYOBI Tools
40V HP Brushless Carbon Fiber Attachment Capable String Trimmer with 4.0 Ah Battery & Charger | RYOBI Tools