The Neptune Space is available in two sizes, Small/Medium and Medium/Large.The sizing and measuring system were designed in accordance with the official measuring procedure used in the Los Alamos Scientific Laboratory Charts at the SBCCOM Mask Fit Facility-Aberdeen Proving Ground (Maryland, USA). Before purchasing a mask, the customer may use the calliper to take two simple face measurements. Using the Full Face Mask Size Recommendation Chart, he or she can evaluate the size category into which the measurements fall. There are three different size categories on the chart: Small/Medium, Both, & Medium/Large. If the measurements fall within the both category, then the diver should technically be able to wear either full face mask (M/L or S/M), and in that case should try on a mask to select the best fit. Please note that the chart boundaries fade. The fading areas represent less common face measurements. It is very likely that a mask will still fit comfortably even if measurements are located in these fading areas.
