This is a synthetic coastal grey slat in wenge style used on the corners of Hot Springs spas and Hot Spot models  Five of these slats are used on each corner of the spa   And one slat which is part number 74106 is used to finish off the corner

Corner Slat, Wenge, Synthetic Redwood Color   Hot Spring Models 2006 - 2015 There are 5 pieces (#74062) on each corner   Each piece has two slats molded into one   Each piece fits together with a tongue and groove style

Espresso Colored corner slat for Limelight and Hotspot SX models beginning in 2012

Corner Panel in Coastal Gray found on Limelights 2012-2017 and Hotspot SX beginning in 2013   This Slat is for the rounded section on the spa This should be replaced when it's cracked, weather-damaged, or rotted