Features typeA ~ boards slide in from side. Skel ~ material removed from bottom surface to reduce fabrication costs. Mounting wells for feet on bottom surface. Two mounting holes to secure bottom board. Slot height increased from 1.7 mm to 1.8 mm to increase process margin for different materials. OBLS board is 3.65" long by 1.9" wide by 1/16" thick. Intended for Developer use case.