Crankwork adapters convert your clipless pedal to flat platform with traction pins - Bikerumor
Amazon.com : Thinvik Clipless Pedal Adapter for Shimano SPD Pedal - Clip Pedal Convert to Universal Platform Pedal - (Only Work on MTB Bike Pedal : Sports & Outdoors
ROCKBROS MTB Flat Pedal Adapter Clipless Platform Adapter Pedal for Shimano SPD | eBay
ROCKBROS MTB Flat Pedal Adapter Clipless Platform Adapter Pedal for Shimano SPD | eBay
Fly Pedals Original Universal Clipless Platform Adapters
Mountain Bike Clipless Pedal Platform Adapter Convert For Shiman Looking Keor System Bike Clip Pedal Adaptor - Bicycle Pedal - AliExpress
Amazon.com: Thinvik Road Bike Clipless Pedal Convert to Flat Pedals,Universal Platform Pedal Adapters for Shimano SPD-SL System Pedal(Only Work on Shimano Road Bike Pedals) : Everything Else
Review: Every cyclist should have Pocket Pedals' slip-on platform pedals - Bikerumor
Crankwork can make your SPDs into flats with its adaptors