Which spikes under a speaker?

I bought a pair of KEF Reference 104/2s that have screw receptacles on the bottoms, suggesting the former owner used some sort of spike. What spikes do people like to use? Are the threads standard?

The 104/2s sit on medium pile carpet, and I'm very pleased with their sound. Frequencies below 80 Hz are sent to my Velodyne HGS-15, relieving the 104/2s of real low frequency duty. The KEFs are bi-wired.

AudioPoints or their big brother Sistrum, you can check everything out at www.audiopoints.com.