MEMORANDUM DECISION.

Defendants appeal from a judgment entered against them following a jury trial in Superior Court, Androscoggin County, to determine whether they were entitled to set-offs against plaintiffs’ claims. We affirm the judgment.

First, defendants contend that the presiding justice improperly excluded testimony about the operating capacity of a radio transmitter as not constituting proper rebuttal. The presiding justice’s determination of what constitutes proper rebuttal *1379must be paid considerable deference on appeal, as “he alone has the opportunity to assess the evidence with the benefit of having heard the testimony sought to be rebutted and of observing the way it went in before the jury.” Payson v. Bombardier, Ltd., 435 A.2d 411, 413 (Me. 1981). On our review of the record, we find no error in the presiding justice’s ruling.

Defendants also argue that the presiding justice erred in refusing to permit them to question one of their expert witnesses about the transmitter’s compliance with FCC regulations. The record, however, again reveals no error in the presiding justice’s ruling.

The entry is:

Judgment affirmed.

All concurring.