The largest dressing size for the UNO is 25 x 25cm. The wound must be 80% smaller than this size in diameter otherwise the patient will require the XLR8+ pump.
In terms of depth, the UNO can service a wound up to 2cm without a filler due to the flexibility of the silicone liner adhesive. The dressing will expand into the cavity 2cm without packing.
For wound depths of 2–5cm, a filler is required. The filler must touch the dressing and wound to drain properly.
Finally, consider the amount of exudate from the wound. More than 70ml exudate a day indicates the use of the XLR8+ pump which will be more cost effective.
The UNO can run two dressings using a Y-connector but consider the point about exudate levels above.