This is a 4 leaf barndoor set for the LTM 2.5 and 4K HMI light, or any other fixture that accepts a 15-1/2" accessory.

Barndoors narrow the beam spread of a light fixture. They help create a 3-dimensional look to a lighting scheme by placing light in a specific area, or by keeping it away.

The more leaves a barndoor set has, or the longer the leaves the more precisely the beam can be controlled.