Santi BZ400 Extreme Heated Undersuit – Made to Measure

From: £579.00 + VAT

Santi BZ400 Extreme Heated Undersuit – Made to Measure comprehensively protects the whole body from the cold. It heats the trunk, thighs and arms evenly. It is designed to be worn on top of a thin base layer allowing most of the generated heat to be passed directly to the diver’s body.

SKU: 2024M.MTM Category:

Santi BZ400 Extreme Heated Undersuit – Made to Measure is designed to comprehensively protect the whole body of a diver from the cold. The heated undersuit heats the trunk, thighs and arms evenly.

The BZ400 Extreme Heated Undersuit is designed to be worn on top of a thin base layer allowing most of the generated heat to be passed directly to the diver’s body.

The heated Santi undersuit gives you the best thermal protection underwater. It keeps you warm and comfortable while heating, even when the batteries are low or completely drained.

The new generation of heating wire is covered with ultra-soft, silicone isolation resistant to breaking. Innovative, synthetic power cable is resistant to high temperatures and cuts.

Santi BZ400 Extreme Heated Undersuit – Made to Measure works only with Santi Drysuit Connector or Thermovalve. Don’t combine with other connectors or batteries higher than 12V

Santi BZ400 Extreme Heated Undersuit specifications

  • Operating time on 24Ah battery: approx. 2h 30min – 3h
  • Made of BZ400 (420g/m2) Thinsulate™
  • Built in heating glove wires
  • Handy pocket on waist for power cord
  • P-valve hose opening
  • Net cuffs with rubber loops for thumbs
  • Elastic gussets under the armpits
  • Two side pockets
  • Elastic waist band
  • Two way entry zipper
  • Foot straps
  • Maximum heating temperature 45°C
  • Heating power: 110 W
  • Safety switch prevents from overheating
  • Wires covered with ultra-soft silicone resistant to breaking
  • Power cable resistant to high temperatures and cuts
  • Undersuit bag included
  • Ladies and men’s cut

Additional information

Weight 23 kg

Female, Male

Measuring Guide


Carefully watch SANTI’s “Instructions for Self-measuring” video below. The video shows all measurements for Made-to-Measure suits.


Download the Santi MADE TO MEASURE FORM. Use only a taylor’s tape measure that has a centimeter scale (only use metric with cm).

Never take your own measurements yourself! Measurements should be taken by another person to make sure all measurements are taken tight up to the body and at correct placement for a specific measurement.

It is important that you stand straight, look forward and do not bend over while you are being measured. It is equally important to take the measurements only while wearing thin clothing, close to the body. Don’t leave any additional measurement allowance.

HEAD – approximately 1cm above the eyebrows to choose the correct hood size.
NECK – above the t-shirt line, under the Adam’s apple and the end of the neck.
BODY TRUNK – hold one end of the tape on the central point of the neck end and lead the tape across the crotch to the back. Mark the place where tape ends and measure the rest of the line to the spine neck bone. Make sure the tape is close to the body including all the curves.
SHOULDER TO SHOULDER – back shoulders length from one top arm bone to another.
OUTER ARM LENGHT – from the back neck spine bone to the wrist while the arm is fully stretched.
INSIDE ARM LENGHT – from armpit to wrist.
LADIES ONLY / SIDE TRUNK LENGHT – from the armpit to the waist line.
BICEPS – widest point on the loose arm. If you have a visibly athletic figure it is advised to measure the biceps also with bent elbow.
FOREARM – in the widest point.
WRIST – between the palm and the wrist bone.
CHEST – first measure the chest in rest and then after breathing in air. Normally the difference should be around 3-5cm. For ladies measure in the fullest point of the bust, preferably while wearing a bra.
WAIST – measure on the belly button level. Remember to measure the waist line in the widest point on the belly button line. To measure a female waistline correctly, use any kind of “marker belt” and fasten it around the waist line.
LADIES ONLY / BACK HEIGHT – centrally from the neck spine bone to the waist line marked with the belt.
LADIES ONLY / CHEST HEIGHT – from the soft neck area (where the neck ends) to the bust line in the fullest point.
HIPS – in the fullest point of the buttocks.
THIGH – widest point approximately 5cm from the crotch area.
CROTCH TO KNEE – from crotch to knee.
CROTCH TO FLOOR – hold one end of the measurement tape in a convenient place in the crotch and measure to the heel end.
CALF 1 – measure the calf in the widest point.
CALF 2 – height from the widest point of the calf to the floor.
CALF 3 – measure the calf 20cm from the floor.
ANKLE – measure the ankle on the ankle bone.
FOOT – place the tape on the floor and step on it to measure from end of heal to end of toes.

It is the customers responsibility to choose the correct drysuit size. All drysuits are made to order. Drysuit returns are not accepted under any circumstance unless Underwater Explorers Ltd/DirDirect has made a mistake. We do not take any responsibility for a fit of a made to measure drysuits unless measured by us. All drysuits are individually tested by manufacturers. Any isolated manufacturing fault(s) will be repaired, not replaced, under manufacturers warranty.