The Bear Song IV butterfly knife is a collaboration between BladeRunnerS (BRS) and Bear OPS. It is a lightweight flipper that is designed to be your go-to everyday carry knife. The B-400 model features natural finished aluminum handles with stainless steel spacers and a swappable latch. The pivots have 304 bearing surfaces and phosphorus bronze washers. The ti black finished 1095 high carbon steel clip point blade has a double tang pin design for great performance.