Double Spring Tummy Trimmer Is More Stronger And Durable From The Single Spring Tummy Trimmers. We Made Our Tummy Trimmer From Hard Compressing Dual Springs So It Is More Durable And Not Easy To Deform. Our Tummy Trimmer Is Lightweight, Easy To Store, Easy To Carry, And Easy To Use Anywhere Anytime. Having Weight Of Less The 1kg Kids Can Also Carry This Easily. since It Is Portable It Will Take Less Space For Storage. Non-Slip Boards Will Add Extra Comfort In Your Exercise As Well As Firm Foot Grip Will Give You the Advantage Of Doing Exercise In Proper Form.