Mobility Aids and Equipment Drive, Medical Supplies & Equipment, Mobility & Daily Living Aids, Rollators & Accessories, Walker Accessories, Walkers Replacement Parts for Drive 790 Knee Walkers (Wheel/Caster) Review by RoomPony July 11, 2018 No Comments 16.Caster (Each Part Sold Separately) Replacement Parts for Drive 790 Knee Walkers More Size:16.Caster 16.Caster