ROK Straps says:

The ROK Strap Commuter Stretch Straps come as a Twin Pack and adjust from 300mm to 720mm /12"to 28".

ROK Pack Straps are a great idea for strapping gear on gear, whether for strapping a helmet to a motorcycle, strapping a hold all bag on a push bike or for bush-walking where you can tie your bed roll onto your rucksack/pack. Quick release buckles ensure fast and quite access to gear.

Adjustable ROK™ Straps offer all your securing needs. their patented designs have inherently superior design qualities which make them safer, stronger, longer lasting, and quicker to use than other straps on the market.