The Testo 0554 5570 Digital Manifold Valve Replacement Kit is used for replacing valve positioners on digital manifolds from Testo. Valve positioners for all manifolds are subject to mechanical wear; however, replacing the valve positioners is easy and can be carried out independently on site. With the valve replacement kit, you can replace two valve positioners - on the high pressure and low pressure side or at the two middle connections on the digital manifold. Please order another kit if you would like to replace all 4 valve positioners.