The present invention relates to a novel pivoted tensiometer adapted for use in measuring tension in an intervertebral disc space. The mixed catalyst composition can be used to prepare a first polymer component in a first polymerization reactor stage and then, when an effective activator is added for the second organometallic compound, the catalyst composition can be used to prepare a second polymer composition that is homogeneously blended with the first polymer component. The top most portion of the bag is unsealed forming a tab. The invention further relates to the inbred and hybrid genetic complements of plants of variety CV554829. The target sources are housed in or upon the target source containment base and the target source containment base is supported by an angled support shaft which is supported by a weighted base. This composition has excellent keeping stability because the phytotoxicity reducing agent of the composition does not decompose and crystals do not separate out even when it is kept for a long time.