‘Health Equipment Information’No. 153, published in May 1986, contains evaluation reports on a further four surgical diathermy units. These are the Esckmann TDB-50, the Fischer Bipolator, the Martin Elektrotom SOB and the Pyser Coa-Comp.Technical Assessment was carried out by the staff of the Bioengineering Unit at Cardiff Royal Infirmary and user assessment within Health Authorities in South Wales.For full details of the findings readers should consult‘HEI’153. The following is an extract prepared byDrD. G. Spendley, Senior Physicist at the Cardiff Evaluation Centre.