The P75-A2 is a spring-loaded test probe from the generic P75 family, used to make temporary contact with a test point on a PCB during in-circuit and functional test. It mounts in a matching receptacle in the fixture's probe plate, so a worn probe can be replaced from the top without rewiring.
The A2 cupped tip is the counterpart to the spear-tipped B1: instead of piercing a flat pad it seats over a rounded target, which makes it the right pick for solder-bumped pads, wire ends, and the cut ends of through-hole component leads. The concave face captures the dome and stops the probe walking off-centre, at the cost of needing a target that actually stands proud of the board. At 1.29 mm the tip is large enough that it wants a reasonably open keep-out around the test point.
