Crankwork can make your SPDs into flats with its adaptors
The Lab: TATZE ADD-FLAT Adapter Review | ENDURO Mountainbike Magazine
MOZARTT Pedal adapter Senza for Shimano SPD MTB Clipless pedals, 17,50 €
pp pedal plate | SL | Adapter compatible with Shimano SPD-SL clipless pedals | Converts clipless into flat pedals | No cleats needed | Adding grip and comfort : Amazon.co.uk: Sports & Outdoors
BBB BPD-90 Bike Feet Rest For SPD Clipless Pedal Dual Reflectors Adapters Black 8716683042856 | eBay
Crankwork adapters convert your clipless pedal to flat platform with traction pins - Bikerumor
DEWIN Pedal Adapter, Pedal Platform Adapter SPD Pedal Adapter Aluminum Alloy Bike Bicyle Clipless Pedal Platform Adapters for SPD 1 Pair (Black) : Amazon.co.uk: Sports & Outdoors
MOZARTT Pedal adapter Senza for Shimano SPD MTB Clipless pedals, 17,50 €
Buy THINVIK Clipless Pedal to Convert Flat Pedals,Universal Platform Pedal Adapters for Shimano SPD-SL System PedalOnly Work on Road Bike Pedals Online at Lowest Prices in UK. B07CGP68VD
Review: Every cyclist should have Pocket Pedals' slip-on platform pedals - Bikerumor