"Stroller accessories" refers to additional items or attachments that can be used to enhance or customize a baby stroller, making it more convenient, comfortable, or practical for both the caregiver and the child. Full definition
It also works well with other stroller accessories including cup holders and child trays which it comes with. (ultimatestrollerguide.com)
These drinks holders are great double stroller accessories as they're so versatile: use them for your own drink; or for your children's drinks; or both. (adventurebuggyco.se)
And have a look at our favorite double stroller accessory. (bestoftwins.com)