Diode Dynamics LED Strip Lights High Density SF Switchback Quad 3 In KitHDHalo Technology. These HD LED semi flex strips have been designed from the ground up to be absolutely the brightest, most reliable strips physically possible. Each strip is populated with a large number of high density (HD) LEDs, which are then coated by a diffusing gel, resulting in a perfectly uniform light when turned on. When off, the diffusing gel hides the chips, resulting in a clean, OEM appearance. Sizing: All sizes are listed by total