Attach your Advantage Wheelchair Side Pac to the armrest of scooters and electric wheelchairs on the inside or outside or on the inside of Manual Wheelchair armrests. Side Pac Adapt A Strap System (SP-ADST) has customizable strap lengths, so you can fit it properly to your armrest. You get it all, two large inside pockets, external pen pockets, and an oversized main compartment with a zippered lid pocket.