Ordered the following items from Herbies: 1) for our Zu Omen Definitions to replace the stock carpet spikes - Threaded Stud Glider × 8: Regular, 3/8"-16 / 2"; and 2) for our Rythmic Audio E15 Direct Servo subwoofer that sits on carpet spikes - Cone/Spike Decoupling Glider × 4, Giant / Brass. We received the 5% AudioCircle discount (thanks!), and free shipping due to the order's cost. (I already own a few sets of Herbies Tube dampers.)
The turnaround from ordering to receiving shipment was fast, installation was straightforward, and the results were palpable. I initially flinched when ordering due to the cost, and post-installation flinched because we hadn't pulled the trigger years ago. Great products, thanks again.