C4 Fins Umberto Pelizzari Sideral Soft

The UP fins were born from close collaboration between Umberto Pelizzari and C4: a technopolymer blade and 250 footpocket, designed to combine the latest plastic moulding technologies with the performance Umberto has always sought. Please note: the fins are shipped unassembled. 250 Footpocket The UP fins use the 250 footpocket, the latest evolution of the C4 footpocket: a TPE 75 ShA polymer overmoulded onto a rigid insole transmits energy from the foot to the blade as efficiently as possible. Careful geometry design has allowed for minimal thicknesses, reducing the weight of the 250 footpocket (size 41/42 EU) to just 250 g (8.8 oz). The reduced mass minimises the energy needed for movement, reducing muscle fatigue; the rigid connection between footpocket and blade, via the internal insole, transmits force with high efficiency. The spar-less blade attachment system, created by C4 in 2006, allows the blade to flex elastically along its entire length. The 3° pre-shaped anatomy makes the fit particularly comfortable, with thin walls that adapt to the foot without constriction. The polymer used is elastic, and the internal insole ensures a footpocket that's rigid in the sole but comfortable in the upper. The blade is attached with a single sturdy M6 screw, for quick assembly/disassembly and a reduced footprint when travelling. Technopolymer blade The UP blades are engineered with a selection of quality materials, an eye-catching design, and technologically advanced production. Numerous polymers were tested and selected, with two specific compounds chosen — one for the Soft version and one for the Medium — to guarantee high performance and durability. The water rails are overmoulded directly onto the blades (length 30.2 cm / 11.9 in, variable height up to 17.8 mm / 0.7 in, thickness 3.3 mm / 0.13 in, in thermo-rubber), for maximum control over lateral skidding during finning without interfering with blade performance. The blade features a smooth, glossy central band that widens from the footpocket to the tip, with a carbon-fibre-effect finish on the sides (reversed on the underside) and a tip profile reminiscent of a whale's tail. It is 59 cm (23.2 in) long at the centre and 62.5 cm (24.6 in) at the sides (maximum total length 79.5 cm / 31.3 in; total fin length including footpocket, 91 cm / 35.8 in). Two lateral ribs run along both surfaces (5 cm / 2 in longer on the upper face), with an additional central rib on the other side. On the underside, in front of and behind the footpocket tip, there are two 16 cm (6.3 in) ribs, 15 mm (0.6 in) wide and 9 mm (0.35 in) high, with an almost triangular section. The blade thickness is 3.4 mm (0.13 in) in front of the footpocket, tapering to 1.6 mm (0.06 in) at the tip. The blade angle is 29°, which combined with the footpocket's 3° brings the total to 32°. Reduced weight The UP fins are among the lightest on the market for long-blade polymer fins, weighing under 1,200 g (42 oz) per pair. Made in Italy production All C4 carbon blades have always been moulded in the company's Italian production department. The new department dedicated to plastic moulding also directly produces the 250 footpockets and the UP blades. Technical data Blade dimensions: 625 x 795 mm (24.6 x 31.3 in) Fin dimensions (size 42/43 EU): 625 x 910 mm (24.6 x 35.8 in) Blade stiffness: Medium, Soft Water rail colour: white Variable-geometry water rails, high-pressure overmoulded Footpocket: 250 EU sizes: 36/37 (223x87mm), 38/39 (242x94mm), 40/41 (261x101mm), 41/42 (270x104mm), 42/43 (280x108mm), 43/44 (288x111mm), 44/45 (299x115mm) US/Canada sizes: 4/4.5, 5.5/6, 7/8, 8/9, 8.5/9.5, 9.5/10.5, 11/12 Footpocket pre-shaping: 3° Compatible with: all MB series carbon blades and UP (Umberto Pelizzari) technopolymer blades