🟥SIDE BOX SERIES 2🟥 More OBLIQUE variations, springs vary. It's

A box with two springs on a frictionless table

Zinus 4 in. Profile Split Cal King White Metal Box Spring, No Assembly HD-BIFD-4CK - The Home Depot

Side Bend on Short Box on Pilates Reformer

Boxes 13, 14, and 15 - MEK Woodworks

Crotch For Days!, Side Panels & Grooves

Spring-Joint Box Popular Woodworking

Side Bend on Short Box on Pilates Reformer

Spring-Joint Box Popular Woodworking

Sub-Zero Legacy Model - 42 Classic Side-by-Side Refrigerator/Freezer - Panel Ready (BI-42S/O)