Better than spikes/studs! Best price I could find for the pro version. Bournemouth based based company Safetystock said they were getting deliveries of these in daily as demands are high. I ordered mine today by phone (Thurs) with probable dispatch either Friday (tomorrow) or Monday.
Watch the sizes... I'm an 8.5 - 9 and only need the medium! Here is a guide to the sizes care of a diligent Amazon reviewer;
Here's the sizing info off the actual carton, so you don't make the same annoying and costly mistake I did. For clarity, I've converted them to UK sizes here.
Men: 4.5 - 8 (UK)
Women: 4 - 7.5 (UK)
Men: 8.5 - 10.5 (UK)
Women: 8 - 10 (UK)
Men: 11 - 13 (UK)
Women: 10.5 - 12.5 (UK)
Men: 13.5+ (UK)
Women: 13+ (UK)
The XL size has been made for a yeti, surely?