A self-assembly kit is a product shipped as separate parts that the user must put together before it can be used. In hardware, this often means a board, sensor, cables, housing, and firmware that become a working device only after assembly.
In cyber security, self-assembly kits matter because every extra component and manual step creates an opportunity for tampering, substitution, or misconfiguration. An attacker may replace a part in transit, add a malicious adapter, or exploit a poorly documented assembly process to introduce hardware or firmware compromise. Defenders reduce this risk with tamper-evident packaging, verified part numbers, signed firmware, secure boot, and clear build instructions so the finished system is harder to alter before first use.