Size chart

The Funky Trunks APEX Racing Jammer range comprises World Aquatics Approved competition race suits designed to maximise speed and minimise resistance through the water. Developed in conjunction with international F-Team athletes and regularly performing on the world stage, the APEX range features mid-to-high level compression, warp knit fabric technology, water-repellent finishes, and ultrasonic bonding — built for competitive swimmers who demand the most from their race suit.

Available in sizes 18–34 (UK/US). This size guide covers all three APEX jammer models: the Apex Viper, Apex Predator X, and Apex Oblivion. All share the same size chart based on waist and hip measurements.

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How to Measure — Funky Trunks APEX Jammer
How to measure for Funky Trunks APEX racing jammer

APEX racing jammers are sized on waist and hip measurements. Measure in centimetres with a soft tape measure taken directly against the skin.

  • Waist — measure around the narrowest part of the waistline, usually just above the belly button. Keep the tape parallel to the floor.
  • Hips — measure around the fullest part of the hips and seat, keeping the tape parallel to the floor.
  • Racing suits are compression garments and will feel considerably tighter than training swimwear — this is expected and intentional. If your measurements fall between two sizes, speak to a member of staff at Allens.
Size 18 20 22 24 26 28 30 32 34
UK 18 20 22 24 26 28 30 32 34
US 18 20 22 24 26 28 30 32 34
AUS 18 20 22 24 26 28 30 32 34
Body Measurements (cm)
Waist (cm) 60–65 65–70 70–75 75–80 80–85 85–90 90–95 95–100 100–105
Hips (cm) 65–70 70–75 75–80 80–85 85–90 90–95 95–100 95–100 110–115

UK, US, and AUS sizes are equivalent for this range. Always measure waist and hips for the most accurate fit. Racing suits are compression garments — if between sizes, speak to a member of staff at Allens. Do not use training swimwear sizing as a guide for racing suits.

Apex Viper Jammer
  • World Aquatics Approved racing jammer designed for competitive swimmers at all levels.
  • Mid-level compression with warp knit fabric that moulds to the body to assist with muscle fatigue.
  • Water-repellent finish to reduce resistance and improve speed through the water.
  • Flatlock seams for comfort, integrated drawcord, compressive modesty lining, and waist and leg opening gripper tape for a secure fit.
Apex Predator X Jammer
  • World Aquatics Approved elite performance jammer with internal X design bonding around the hips for added comfort without compromising compression.
  • Ultrasonic bonding with seam tapes designed for high-altitude extreme sports — withstands immense tension while isolating key muscle groups.
  • Advanced water-repellent formula applied to the surface to reduce resistance and improve speed.
Apex Oblivion Jammer
  • World Aquatics Approved elite race suit — part of the new generation of APEX racing suits, designed for competitive swimmers with experience fitting compressive suits.
  • Internal bonding positioned to provide lift in the water and targeted compression, with additional leg compression to maintain body position under fatigue.
  • Latest fabric technology moulds to the body with maximum compression while allowing fluid body movement through every stroke.
  • Advanced water-repellent formula and ultrasonic bonding for maximum speed and durability.
Fit Notes — Funky Trunks APEX Racing Jammer
  • APEX racing jammers are World Aquatics Approved competition race suits — they are designed for racing only. Using them for training will significantly shorten their lifespan and reduce performance properties.
  • Size based on waist and hip measurements. Racing suits are compression garments and will feel considerably tighter than training swimwear — this is normal and expected.
  • The Apex Oblivion is an elite suit designed for competitive swimmers with experience fitting compressive race suits. If you are new to racing suits, the Apex Viper is the recommended starting point.
  • The integrated drawcord and gripper tape on the waist and leg openings help keep the suit in position during dives and turns. Always ensure the drawcord is secured before racing.
  • Care: rinse in cold fresh water immediately after use. Do not machine wash, tumble dry, wring, or expose to prolonged sunlight. Store flat and dry.
  • Unsure? Contact our team or call +44 1827 330600.
Frequently Asked Questions — Funky Trunks APEX Racing Jammer

Measure your waist and hips in centimetres and match to the size table above. UK, US, and AUS sizes are equivalent for this range. Racing suits are compression garments and will feel tighter than training swimwear — do not size up solely to avoid the compression feel. If your measurements fall between two sizes, speak to a member of staff at Allens for advice.

The Apex Viper is the entry point to the APEX range — a World Aquatics Approved jammer with mid-level compression, warp knit fabric, water-repellent finish, and gripper tape. It is suited to competitive swimmers at all levels. The Apex Predator X adds internal X design bonding around the hips and ultrasonic bonding for greater compression and muscle isolation. The Apex Oblivion is the most advanced suit in the range, with internal bonding for lift, maximum compression, and additional leg compression to maintain body position under fatigue — designed for elite swimmers with experience in compressive race suits.

Yes. All three APEX jammer models — the Viper, Predator X, and Oblivion — are World Aquatics Approved for use in sanctioned competitive swimming events. Always check with your governing body or meet officials if you are unsure whether a specific suit is permitted for your competition.

APEX jammers are designed for competition use only. Using them for regular training will significantly reduce their lifespan and compromise their hydrodynamic and compression properties. For training, we recommend the Funky Trunks Training Jammer, which uses ECO C-Infinity chlorine-resistant fabric built for regular pool use.

World Aquatics (formerly FINA) is the international governing body for competitive swimming. A World Aquatics Approved suit has been tested and certified to meet the regulations for use in sanctioned competition, including restrictions on buoyancy, surface texture, and coverage. All APEX jammers in this range carry this approval.

A racing jammer should feel tight and compressive — considerably more so than a training jammer. There should be no excess fabric, bunching, or gaping. The waist and leg grippers should sit flat against the skin. The compression is intentional and designed to support the muscles, reduce drag, and improve body position in the water. If the suit is uncomfortable to the point of restricting breathing or circulation, try the next size up and speak to our team.

Rinse thoroughly in cold fresh water immediately after every use. Do not machine wash, tumble dry, wring, iron, or expose to direct sunlight for extended periods. Store flat and dry, away from sharp objects. Proper care will preserve the water-repellent coating, compression properties, and bonding for longer.

If you are new to racing suits or competing at club level, the Apex Viper is the ideal starting point — it is World Aquatics Approved and offers mid-level compression with all the key race suit features. The Predator X suits swimmers competing at regional or national level who want greater compression and bonding. The Oblivion is designed for elite swimmers with experience in compressive race suits competing at the highest level. Speak to our team at Allens if you would like help choosing the right suit for your level.

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