BRM *is* your point of sale. It prices up your rental, records payment, (it can even process payment via Stripe) prints your invoice (including waiver) and books out your rental item. You can make reservations on the fly when a client is in the store.
But its also much more than just a point of sale. You can use the same screen to make advanced bookings for telephone bookings and email enquiries.
Whether for walk-ins or advanced rentals BRM / RSM tracks your inventory availability.