This is the old style masonry handsaw with a large tungsten carbide tooth pitch of 19mm or 38mm these blades are only used for the soft materials like plaster blocks, lightweight blocks as well as autoclaved aerated concrete blocks (AAC blocks), which they cut very fast.
These handsaws have strong tungsten carbide teeth and have the old style traditional upright tooth design.
2/3 & 1 1/3 TPI