The Petzl Grillon is an amazing versatile and very useful bit of kit. Can used as a flipline or a pole strap or as an adjustble lanayrd for work positioning.
This version comes without an attachment so you have the freedom to choose whatever connector you like.
Here is the Petzl Blurb-
Adjustable lanyard for work positioning
The GRILLON adjustable lanyard is used to make work positioning systems, to complement a fall-arrest system. Its length can be very easily and precisely adjusted as necessary for comfortable positioning at the workstation. Depending on the configuration, it can be used in single or double mode.