We’ve sold a lot of these for Dynaco tube amplifier upgrades; in fact, this part is our largest selling single item. We had feedback from customers requesting marking of the Speaker Impedance value on the terminal blocks. Now for 2025, you can purchase either marked or unmarked terminal blocks and at two price points; the unmarked Block is unchanged @ $27.50 and the marked blocks are $37.50. We offer these on our website, as well as our eBay online store.