This Pololu 1×40 straight male header is a 0.1\" (2.54 mm) pitch breakaway pin strip with extra-long pins on both sides of the plastic spacer. You can snap or cut it to the exact length you need, making it a handy “one part fits many jobs” connector for prototyping and custom wiring.

Compatibility-wise, the 2.54 mm spacing matches standard Arduino shield headers, breadboards, perfboard/stripboard and most 0.1\" female sockets. The key difference from typical male headers is the double-sided long pins: it can act as a female-to-male adapter when plugged into a female header, and both ends are suitable for wire-wrap. It’s not the right choice where you specifically need short solder tails (for low-profile builds or guaranteed standoff height), or where the mating connector expects a different pitch.

Typical uses include making removable connections between boards, bringing signals through a board so you can connect on both sides, building quick adapter “stacks” with female headers, and wire-wrap prototyping without needing a separate long-tail pin strip. Compared with standard breakaway male headers (short solder side), this one is more versatile for pass-through and wire-wrap, but can sit taller and may be less tidy in tight enclosures.

Useful complements: pair it with matching 0.1\" female headers for plug-in adapters, or use it with prototyping boards for permanent builds.