Santi Ladies First BZ400X Undergarment

The Ladies First BZ400X undersuit is ideal for long dives in extremely difficult conditions.


Ladies First undersuit, with great, feminine design basing on BZ400X style is the warmest undergarment in our offer. New details proposal underlines the feminine look and goes in line with Ladies First drysuit. It is designed for diving in water temperature less than 45 degrees F. It is also ideal for long deep diving, with decompression.

Thinsulate BZ 400 insulation is recommended by 3M as optimal for diving undersuits, because it is compressed and doesn’t take too much space under the dry suit. It also has a net layer, which makes the undersuit even more durable and practically indestructible.

Undergarment designed for women who value individuality and comfort even during long and demanding dives at temperatures less than 7 °C. Built on the experience of leading divers and instructors of recreational and technical diving. The modern, well-fitting and feminine cut is complemented by three color details that allows you to create the perfect combination of the Ladies First drysuit.

Making this model we used the best materials and available technologies. Thinsulate™ BZ400 Insulation is recommended by leading fabrics producers. Thanks to their effective insulation, resistance to moisture and breathability it is one of the best insulation which can be used in undergarments. It is compressed and do not take too much space under the drysuit, does not restrict the movement of the diver. It has a net layer, which makes the undersuit even more durable and practically indestructible.


  • Thinsulate™ BZ400 Insulation
  • the lining: Micropolar weight 420 g/m˛, warmth: 1,80 CLO
  • the outside layer: Polyamide, Polyester
  • weight: 2,1 kg.


  • details available in 3 colors: fuchsia, lime, grey
  • two large pockets on thighs
  • one inside pocket on the left chest
  • comfortable zipper opening flap on the bottom
  • tapes, which supply air to dry gloves
  • elegant and comfort collar and yoke covered with soft shell
  • two-way zip
  • reinforcing patches on knees, shoulders and back made of Polyester
  • in waist-elastic gusset made of windproof fabric
  • shoulder gussets allowing more free movement
  • inside suspenders
  • wide (10cm) elastic ankle bands prevent moving up the legs when setting up the drysuit

Additional options:

  • name patch in the selected color options: fuchsia/lime/grey
  • heating system adaptive holes (right/left over waist line)

See the sizing chart here.