When a projector lamp reaches end of life, the fastest path back to service is a correct replacement part. The BTI DT01171-BTI is built for Hitachi CP-K1155 and CP-WX4021 projectors, giving IT and AV teams a practical way to restore brightness without replacing the entire unit. This lamp is intended for environments where projection uptime matters: conference rooms, classrooms, training spaces, and shared collaboration areas. By matching the compatible projector models, it helps reduce troubleshooting time and keeps maintenance straightforward for support teams managing multiple rooms. Choosing the right replacement lamp is about more than getting the projector back on. It is about preserving the investment already made in mounted displays, cabling, and room integration. A correct lamp replacement helps maintain image quality, supports predictable service cycles, and avoids the cost and disruption of premature projector replacement. For organizations that value continuity, this BTI lamp is a focused, cost-effective maintenance part for keeping Hitachi projection systems in circulation.