Ark kompact 2nd side rail kit gray the kompact second side rail kit includes 5 balusters, 1 solid beech wood handrail and all necessary hardware. This rail kit increases the dimension of the staircase by 1-1/2 in. It is designed to complement the ark kompact staircase series. Depending on the stair installation you may need 2 or more second side rail kits. Please refer to the installation and configuration guides. features: for installation with kompact modular staircase only constructed from steel handrail constructed from solid beech wood hi-gloss black color designed to fit kompact model k35003, k35018, k35025 and k35028 this item is not suitable for exterior installation.