30 Blue Orchard Mason Bees, not in tubes, with a small wooden release box.
There are two different patterns on the lid of the boxes. One pattern is stripes and the other is a checkerboard pattern.
When you receive your cocoons and box, unpack the cocoons and place them in the box. Then you can place the box inside your bee house if there is room, or place it on top or near the house. When the mason bees emerge from the cocoons they will exit the box through holes drilled in the side.