What • Spiked slippers that pull over shoes to provide traction on ice and slick, outdoor surfaces.

How much • $15 to $20. Advanced models are more. Prices vary widely among merchants.

Where to buy • Visit Surefoot.net to look at the products. Many sporting goods and hardware stores have them in-house or online.

Why buy it • Traction aids are a godsend for icy, snow-packed sidewalks and steps. Pull them over the shoe and six tungsten carbide spikes gouge for traction. Practice indoors on a carpet to learn to pull them over the toes, heals and sides properly. They're prone to slip off when damp if they're not secure. Replacement spikes are available. The "All Purpose" model is for people who work and play outdoors — overkill for merely walking on sidewalks and steps. The "All Purpose" isn't always in stores, so check websites. YakTrax makes a model using coils instead of spikes. But they're better for ground rather than sidewalks and steps. Visit yaktrax.com.