The Tank Dolly® uses 3 interchangeable tank straps

The adjustable STO-08D Tank Strap secures 1 or 2 scuba tanks independent of the other ⏤ without a BCD or a backplate, harness, and wing attached to either tank

• The adjustable STO-08D Tank Strap encompass a diameter from 5.5 to 8 inches (13.9 to 20.3 cm) for each scuba tank
  
  
• The 2 most common scuba tank diameters are 7.25 and 8 inches (18.4 to 20.3 cm)
  
  
• Currently, there's not a scuba tank used by divers with a diameter exceeding 8.03 inches (20.4 cm)   

The adjustable STB-34C Tank Strap secures 1 or 2 scuba tanks independent of the other ⏤ with a BCD or a backplate, harness, and wing attached to either tank

• Fully assembling your rig on land eliminates the need to assemble your rig on a crowded boat and while crossing rough water
  
  
• The adjustable STB-34C Tank Strap encompass a circumference up to 34 inches (50.8 cm) for each scuba tank and attached BCD
  
  
• Attach your BCD and 1st stage to your tank then clip your regulators to your BCD
  
  
• Additional gear may be clipped to your BCD, backplate, or harness
  
  
• Your rig will be in “dive ready” condition (obviously, your air is off until you are ready to enter in the water)

The adjustable Doubles Tank Strap will secure 2 scuba tanks connected by tank bands, a manifold, and attached to a backplate, harness, and wing (Doubles are also referred to as Twins)  

• Place your fully assembled Doubles rig on your Tank Dolly® and secure with the Doubles Tank Strap
  
  
• The adjustable Doubles Tank Strap is expandable to a length of 28 linear inches (71.12 cm)

So are we ⏤ Shark Tip:

• Use a carabiner with a 1/4 inch (6 mm) or less diameter
  
  
• Place the carabiner through the bottom 1/4 inch (6 mm) hole on the Tank Brace
  
  
• Clip the strap's 316 stainless-steel D-ring to the carabiner
  
  
• This procedure can be used with all of our straps (DTS-28L, STO-08D, and STB-34C)
  
  
• The above photo depicts DTS-28L Tank Strap used with 7.25 inch (18.4 cm) tanks (Doubles rig)