<input
    type="numer"
    value="{{ item.count }}"
    min="1"
    max="{{ item.existencia }}"
    name="{{ item.product_id }}_cant"
    (keypress)="onlyNumberKey($event)"
    [(ngModel)]="cantidadItems.cantidad"
    id="cant_producto{{ item.product_id }}"
    (change)="cambiacantidad(this.item)"
/>