Pogo Pin Probe Clip - 2x5 1.27mm Pitch SWD : ID 5434 : $19.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Amazon.com: Treedix 10PCS Gold Plated Spring Loaded Thimble Pogo Pin 7.5mm Long Pin Male Spring Pogopin Header Target Connector Through Hold PCB (2 Pin Male) : Toys & Games
Four common design schemes for Pogo Pin
Pogo pins - High durability spring-loaded contacts | ATTEND