The Sliding Rack Mount and its included spacers may be shipped separately (except for the 3×3" version). Multiple Size Options: Available for 2×2", 2×3", 2×4", 3×3", 3×4", and 4×4" rack uprights, plus specialty rack compatibility Universal Hole Diameter: All sizes accommodate rack holes from 5/8" to 1" Adjust Height in Seconds: Release buttons to reposition VOLTRA I in seconds between exercises Secure Locking Mechanism: Dual-lock system confirms proper engagement before training Durable Construction: Engineered for repeated daily use in demanding training environments Spec 3×3" Version: Product Dimensions (L×W×H): 8.5" × 7.8" × 3.7" (217 × 197 × 94 mm) Other Sizes: Product Dimensions (L×W×H): 11.1" × 9.0" × 3.7" (281 × 228 × 94 mm)