GEM Adjustable Swivel Clamps - Model: ST-2 HOLE SIZE: 1/4 x 5/16" Go to amazon.com Related posts Top 10 indicator holder clamp for 2022 FeatureCondition - BRAND NEW IN ORIGINAL PACKAGINGWarranty - 1 YEARManufacturer - GEMSOUND DescriptionGEM Adjustable Swivel Clamps - Model: ST-2 HOLE SIZE: 1/4 x 5/16"