Our “Pivoted Turnbuckle” is the most Efficient, Powerful Expandable Manhole Riser on the Market. American Highway Products Ltd. Manhole Riser is used to reduce cost and stream line the adjusting of utilities lids to the new grade when paving a road. Its unique pivoted turnbuckle linkage ensures a pressed in bearing fit when installed. The Pivoted Linkage will contract and expand the Manhole Riser ½”, giving a full 1” diametric variance, thus allowing the flexibility to work on different diameter frames. Utilizing a Pivoted Turnbuckle Manhole Riser from American Highway Products Ltd.