C4 - Sideral HT


C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
C4 - Sideral HT
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Load image into Gallery viewer, C4 - Sideral HT
Load image into Gallery viewer, C4 - Sideral HT
Load image into Gallery viewer, C4 - Sideral HT
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Regular price SFr. 550.00

Unit price per 

Sideral HT

The SIDERAL HT Bi-fins are extremely bright and shiny. Thanks to these features they increase the safety of deep sea free divers and they also create a “flasher” effect very useful for blue water hunting.

SIDERAL HT feature an essential design which is the result of years of study and research in applied biomechanics. The fins are ideal for the most demanding freedivers with regards to performance, efficiency and speed.

Thanks to the terminal flap, SIDERAL HT can be used at high speed while freediving or spearfishing


Sideral HT are made in 100% carbon fiber HyperTech TR50 and they are inserted in the foot pocket all the way to the heel for an excellent transmission of energy.

Thanks to more than thirty years of studies and worldwide records, we have been able to develop the DPC (Double Parabolic Curve) design featured by the SIDERAL HT. This design has now been enhanced thanks to a special lamination of the layers of carbon, specifically dimensioned and positioned.

The D.P.C curve optimizes the bending of the blades and the quantity of water processed pairing with the Elastic-K10 water rails optimizing the strength produced by the muscles and articulations.

The level of energy is optimized allowing for greater speed and therefore safety when diving.  The less tired we are the safer we can dive: this is the condition of passive safety to be pursued at all times.

SIDERAL HT feature blades that are specifically symmetrical therefore increasing mechanical and dynamic efficiency. This solution reduces energy dispersion and torque forces which are typical of asymmetric geometries.

A reduced mechanical load also increases the duration of the composite fibers.

SIDERAL HT are made in 100% carbon HT ALU 15 T, aluminized on the surface for a shiny flasher effect. The HyperTech fiber is 40% more resistant than other standard fibers and it features a high level of resistance and excellent elasticity.

The new weave design of the HT ALU 15 T featuring 15mm large bands layered in a fishbone pattern, greatly reduces the number of intersections of the weaving that cause viscose friction in the fabric itself. Because the fibres are less.

This special weave, with a reduced number of intersections, makes the blades more flexible and efficient thanks to a reduced absorption of energy.

The blades of SIDERAL HT are connected to the foot pocket thanks to a mechanical  insert that is blocked by two special screws that cannot go easily unscrewed, providing a safe and efficient connection.

For easy transportation, SIDERAL HT can be disassembled, so as to reduce their volume and any chance of damage.


  • C4 300 Footpockets
  • Fin Bag


The 300 2.0 easy fit foot pocket, available in 9 different sizes, prevent dispersion of energy greatly reducing the space between the shoe and foot.  Efficiency is therefore maximised.

300 2.0 Easy Fit foot pockets feature a very low mass therefore maximizing the performance by minimizing the effort of the diver.

The new footpockets  300 2.0 Easy Fit, an evolution of C4 300 footpockets, are extremely light, resistant to wear and preformed at an angle of 3°. Thanks to the new fit, named “Easy Fit”, and to the new anatomical shape, named “Best”, they are very comfortable and easy to wear. They are featured in 9 sizes and, from size 40 to size 44, they are available in each single size.



  • Material: HT ALU 15T
  • Blade Dimension: 1000mm long and 197mm wide
  • Blade hardness: 25 Soft, 30 Medium
  • Water Rails: Elastic-K10 Black
  • Weight: 600 gr
  • The angle of the blades is 29° + 3° of the preformed footpocket for a total inclination of  32°.
  • All C4 blades models are compatible with both the 300 and the 400 footpockets
  • Blade length: Use type: Mix Open Water / Pool, Mostly laying on the bottom in ambush, Oper Water Freediving


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Sold out? You couldn't find what you are looking for? You want to combine other materials or design your personal wetsuit? You only need pants but no top? Our shop is showing the most selling combinations and materials. But we do offer a lot more on request - simply contact us!

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