Based on this product's specifications, here are some alternatives and similar models
Tubular Road Tyre Pirelli P Zero Race 26" 26-622 120 TPI 205 g
Summary description:
Pirelli P Zero Race is a 26" tubular road tyre designed for competition and fast road riding. Size ISO 26-622 (ETRTO), carcass density 120 TPI and weight approx. 205 g provide a balance of low rolling resistance and ride compliance. Intended for tubular-compatible rims; suitable for racing, training and high-performance road use.