Rockler Clamp It® Assembly Square 8 1 1/2"

Amazon

Strong plastic construction Clamps on inside or outside of a corner Ideal for assembling drawers with lipped fronts Holds deck balusters at a perfect 90° angle while fastening Eliminates need for long, bulky clamps, Weight: 0.13 Pounds, Manufacturer: Rockler

Electrical World

Strong, plastic assembly square clamps on either the inside or outside of a corner. Ideal for assembling drawers with lipped fronts. Holds deck balusters at a perfect 90° angle while fastening. Size 203mm (8") x 38mm (1-1/2").

Zoro Tools

Strong, plastic assembly square clamps on either the inside or outside of a corner. Ideal for assembling drawers with lipped fronts. Holds deck balusters at a perfect 90 angle while fastening. Size 203mm (8") x 38mm (1-1/2") .