insulated circular socket in the 16BL series from Stäubli is designated as Stäubli 15

The description of the application comes directly from the manufacturer's product text

AC 1000 V / DC 1500 V

T0052919399N

Drytex sokker str. 36-39 MIL18710101421 insulated circular socket in the. Drytex socks have been engineered to wick moisture and heat from the surface of the feet. These technical socks are ideal for indoor work when wearing sandals and shoes, and toe capped shoes in summer conditions. The socks have a Cordura reinforced heel and toes. ESD approved. Composition: 50% polyester, 41% polyamide, 6% Cordura polyamide, 2% elastane and 1% carbon fibre.