SLR / Extension Rings / Sea & Sea Extension Ring 20L with Port Lock CloseSea & Sea Extension Ring 20L with Port Lock Zoom Sea & Sea Extension Ring 20L with Port Lock SKU: # ss-30123 FREE Standard Shipping to USA / Canada! Price $279.95 Options Back Item IncomeAccount TaxCode Mapping UDF1 UDF2 UPC Code Pick Up Tax Amount Quantity -+ Add to Cart Add to Cart Custom Options Price as Configured Add to Cart View Cart Articles & Videos About This Item ALL ARTICLES ALL VIDEOS Overview / Product Description Sea & Sea Extension Ring 20L with Port LockSpecifications[Dimensions (DIAxD)] 129 x 35.5mm / 5.1 x 1.4 inches[Weight] Approx. 154g / 5.4 oz[Depth rating] 100m / 330ft[Construction] Corrosion-resistant aluminum alloy (alumite coating)[Distance] Between the mount and the front end: 20mm / 0.8 inches (with port lock)