Ramset 100 Pack .25 Caliber #4RS25 Yellow Fastener Load. Ramset powder loads provide the performance and power you need to penetrate hollow block and concrete. The loads are color coded yellow and are at power level 4. When beginning projects use lower level loads and move into higher load if fastener does not set completely. The .25 caliber yellow fastener load is to be used with Hilt model DX-35.