A reinforcement of even the finest details is the goal of all cable design. A traditional cable can, however, not achieve that quality, due to the construction. A good interconnect must have low capacitance and low skin-effect. 
The skin-effect has a dynamic and noticeable influence because an audio signal is nothing but variations of frequencies and sound levels. If we were to transfer only one stable frequency the skin-effect would not be any problem. The frequencies push the signal differently far out from the centre of the conductor. High frequencies travel on the surface whereas low frequencies travel inside the conductor. 
Thus, the higher the frequency, the higher the resistance. 
In order to minimize the skin-effect the EFF-I is designed in accordance with Equalized Frequency Flow (EFF) Technique. It is based on tube shaped conductors with a wall thickness of 0.20mm, which is well below the smallest skin depth within the Audio range. This allows the same resistance for all frequencies. The result is a transparent and exact reinforcement with clear room definition. 
EFF-I One of SUPRA´s most awarded products, not without good reason...

EFF-ISL
Analogue interconnect. 
Designed for minimized skin-effect. Best applied between CD/pre-amp and power amp. Enhances transients and timing for true sound performance. Supplied with SUPRA PPSL RCA connectors with squeeze locking.