Based on this product's specifications, here are some alternatives and similar models
Tryton saw blade nut and washer set for THP1300 circular saw — 2 pieces (YTHP13NP)
Summary description:
Replacement nut and washer set for Tryton THP1300 circular (table/hand) saw blade. The kit contains two components designed to secure the saw blade on compatible THP1300 models. Intended for blade mounting and safe clamping during cutting operations; suitable for maintenance, blade replacements and ensuring stable, vibration-reduced performance.