The SpeedRing for Bron Pulso from Profoto enables Profoto heat-resistant (HR) softboxes to be compatible with Bron Pulso flashes. By using Profoto speedrings compatible with specific flashes you can continue to use one softbox brand with various types of flashes. The durable heat-resistant metal speedring adapters are designed so that the HR softboxes can be rotated 360°.