Training Belt
From Amazon
Granite Rockband MTB Frame Carrier Strap for Inner Tubes and Bike Tool Kit, Bike Storage Solution for Attaching Extra Gear on Your Mountain Bike, BMX Bike, Road Bike and Gravel Bike (Black)
Sigma Sports
Granite Design Rockband Carrier Belt Strap - 450mm
Chevin Cycles
Granite Rockband 450mm Carrier Belt Strap in Black