9V battery clip with 5.5mm/2.1mm plug : ID 80 : $2.95 : Adafruit Industries, Unique & fun DIY electronics and kits
9 Volt Battery Connector/Snap Plug – Circuit Uncle
JST Battery adaptor: Dual battery adaptor for connection to 9V batteries.
9 Volt Battery Snap Connector - Pack of 2 - Dallee Electronics
Warwick 9V Battery Clip – Thomann United States
9V Battery Snap Connector - Solarbotics Ltd.
Battery Connector, 9-volt
Amazon.com: 9V Battery Connector,10 PCS T-Type 9 Volt Battery Buckle Connector Hard Buckle Plastic Shell Used in Student Experiment,or Other Equipment with 9V Battery(T-Type, 10PCS) : Electronics
9 Volt Battery Connector for Guitar & Bass
Amazon.com: Parts Express 9V Battery Clip l Type (1) : Electronics
2 Pcs 9 Volt Battery Clip Connector I Type Hard Shell Buckle Holder 15cm Wire - Walmart.com
9V Battery Clip Cable
Amazon.com: SDTC Tech 5pcs T Type 9V Battery Clip Connector Positive Negative Snap Lead Wire(15cm) : Electronics