Tractel Rollclamp Dover Medium Clamp H and I Beam Anchor. this has been used, still working perfect. all ready for work. 
The Tractel Rollclamp has nylon rollers allowing the anchor to move along the beam ensuring complete freedom of movement for the user. Available in two sizes: Size M - corresponding to a “I” beam with a flange 380 mm max width (adjustable from 120mm) / Size L, corresponding to a “I” beam with a flange 640 mm max width (adjustable from 120mm). Can be installed on the upper or lower soleplate.
The Rollclamp is EN795:1996 class B with a static strength of 10kN and capable of taking a 6kN dynamic load. We have had confirmation from Tractel that it can be used for aiding but NOT suspended rope access due to the potential fatigue in the plastic rollers if used in this manner (the rollers may become compressed).