When it comes to buying balances for weighing, there is only one website that features only the most reliable and affordable brands like Ohaus, Rice Lake, A&D Weighing, Salter Brecknell and Adam Equipment along with an outstanding selection of calibration test weights to calibrate your balance. The weights are available in kits or individually. Grip handle weights are also available in stainless steel or cast iron.  Salter Brecknell lab balances has the balance for sale that you are looking for. Many of the Salter lab balances on sale are available with external calibration. Many are also available with RS-232 serial ports.  Are you looking to connect your balance to your computer? Take a look at the Adam Equipment balances and the Adam DU easy to use data collection software. Stainless Steel Class Class F Test Weights  are also available.