centre tool screw BrE technical
center trap AmE technical

And then she thought: there must be a center trap.

Max held on the center trap as he took a deep breath.

And on the floor of the opening, she could just make out the outlines of the center trap.

Max turned towards the center trap as the bird boy refilled the empty one on the end.

Max raised the shotgun to his shoulder and put the front gold bead on the base of the center trap.

The shooter held his shotgun aimed at the center trap, and called 'pull' when he was ready to have a bird released.

In the center trap.

The center trap!

Some light came from right above them, thin lines of light from around the center trap opening, and there were similar lines of light where the left- and right-side traps were.

Finally, the antennae pigments are quenched, as observed by the effect of O2 on the O-level fluorescence yield, when all photochemical system II reaction center traps are presumably open. The O2 pressure required for half-quenching in this case was about 400 atm.