The park tool pcs ext repair stand extension is an extension for pre 2001 pcs 1 and pcs 4 repair stands the kit includes a quick release collar and extension tube to raise the working height of the stand the pcs ext is required for use of the 106 ac park tool pcs ext repair stand extension features the pcs extension adds up to 53 cm of height to the pcs 1 home mechanic repair stand creates a comfortable working height wherever the bike is clamped quick release collar allows