Castelli T.O. ALII Run Men's Triathlon Top (Black/Red)

This product comes into the Castelli lineup as a direct request from Timothy O’Donnell when he wanted to do better than his fifth place Kona finish. The objective is clear: keep cool and comfortable during the run. We took our insanely light and ventilated A-Vent fabric and gave it a loosish cut to allow maximum airflow between the top and the body. The top weighs next to nothing but covers a wide range of conditions: the fabric is excellent at keeping you dry when you want it too but really shines when you need cooling and can pour water over it at the aid stations.

Super lightweight to keep you cool on the move. The Castelli T.O. ALII Run Top is perfect for hot weather racing. The looser fit allows more ventilation between the top and the body, which is further helped by the open-mesh knit. The UPF 15 rating blocks 93% of UV rays, so you’re protected from sun damage.

Key Features

• Ultra-lightweight A-Vent fabric for maximum breathability

• Looser fit design for improved airflow and cooling

• Open-mesh knit structure enhances ventilation

• Quick-drying material ideal for hot weather racing

• Designed with input from pro triathlete Timothy O’Donnell

• Excellent moisture management to keep you dry

• Suitable for pouring water during races for instant cooling

• UPF 15 protection blocks 93% of UV rays

Product Specifications

• Brand: Castelli

• Product Name: T.O. ALII Run Men's Triathlon Top

• Color: Black/Red

• Fabric: A-Vent lightweight ventilated fabric

• Fit Type: Relaxed / breathable fit

• Sleeve Type: Sleeveless

• UV Protection: UPF 15 (blocks 93% UV rays)

• Usage: Triathlon run segment, hot weather racing

Cooling & Ventilation Performance

This triathlon top is specifically engineered to perform in hot and demanding conditions. The A-Vent fabric promotes continuous airflow, helping reduce heat buildup during long runs. The open mesh structure allows sweat and moisture to evaporate quickly, while also enabling rapid cooling when water is applied. This makes it highly effective during races where temperature control is critical. The loose fit further enhances ventilation, ensuring you stay comfortable even at peak effort.

Easy Operation / Usage

• Wear during the run segment of triathlon or endurance events

• Pair with tri shorts or suit for complete race setup

• Pour water over the fabric at aid stations for instant cooling

• Ideal for high-temperature and humid conditions

Why Choose This Product

• Designed specifically for hot weather performance

• Keeps you cool, dry, and comfortable during intense runs

• Lightweight feel reduces fatigue and distraction

• Trusted design inspired by professional athletes

• Excellent balance of protection, ventilation, and comfort

In the Box

• 1 x Castelli T.O. ALII Run Men's Triathlon Top